<!--- Verify first that your issue is not already reported on GitHub -->
<!--- Also test if the latest release and devel branch are affected too -->
<!--- Complete *all* sections as described, this form is processed automatically -->

##### SUMMARY
docker_container is not idempotent when specifying an ip address

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
docker_container

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
ansible 2.8.5
  config file = /home/pkueck/projects/cix.de/cix-ansible/ansible.cfg
  configured module search path = ['/home/xxx/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python3.7/site-packages/ansible
  executable location = /usr/bin/ansible
  python version = 3.7.4 (default, Jul  9 2019, 16:32:37) [GCC 9.1.1 20190503 (Red Hat 9.1.1-1)]
```

##### CONFIGURATION
<!--- Paste verbatim output from "ansible-config dump --only-changed" between quotes -->
```paste below
n/a
```

##### OS / ENVIRONMENT
<!--- Provide all relevant information below, e.g. target OS versions, network device firmware, etc. -->
Fedora 30, CentOS 7

##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->

<!--- Paste example playbooks or commands between quotes below -->
```yaml
---
- hosts: myhost
  gather_facts: no
  tasks:
    - docker_network:
        name: "foonet"
        ipam_config:
          - subnet: 172.16.44.0/24
    - docker_container:
        name: "foo"
        state: present
        image: centos
        networks:
          - name: foonet
            ipv4_address: "172.16.44.11"
        networks_cli_compatible: yes
      loop: [1,2]
```

<!--- HINT: You can paste gist.github.com links for larger files -->

##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->
container created on first loop cycle, not touched on second one

##### ACTUAL RESULTS
<!--- Describe what actually happened. If possible run with extra verbosity (-vvvv) -->

<!--- Paste verbatim command output between quotes -->
```paste below
PLAY [myhost] ***************

TASK [docker_network] *******
ok: [myhost]

TASK [docker_container] *****
--- before
+++ after
@@ -1,9 +1,10 @@
 {
-    "exists": false,
+    "exists": true,
     "network.foonet": {
         "aliases": null,
-        "ipv4_address": "",
-        "ipv6_address": "",
+        "id": "27e539c3b9af0160f02a0532ad081d1bd1ef3dd93e652095ec96d6dfd95bf2fb",
+        "ipv4_address": "172.16.44.11",
+        "ipv6_address": null,
         "links": null,
         "name": "foonet"
     }

changed: [myhost] => (item=1)
--- before
+++ after
@@ -1,10 +1,9 @@
 {
     "network.foonet": {
-        "aliases": [
-            "44cfded131d7"
-        ],
-        "ipv4_address": "",
-        "ipv6_address": "",
+        "aliases": null,
+        "id": "27e539c3b9af0160f02a0532ad081d1bd1ef3dd93e652095ec96d6dfd95bf2fb",
+        "ipv4_address": "172.16.44.11",
+        "ipv6_address": null,
         "links": null,
         "name": "foonet"
     }

changed: [myhost] => (item=2)
```

version_added: "2.7"
  cleanup:
    description:
      - Use with I(detach=false) to remove the container after successful execution.
    type: bool
    default: no
    version_added: "2.2"
  command:
    description:
      - Command to execute when the container starts.
        A command may be either a string or a list.
      - Prior to version 2.4, strings were split on commas.
    type: raw
  comparisons:
    description:
      - Allows to specify how properties of existing containers are compared with
        module options to decide whether the container should be recreated / updated
        or not. Only options which correspond to the state of a container as handled
        by the Docker daemon can be specified, as well as C(networks).
      - Must be a dictionary specifying for an option one of the keys C(strict), C(ignore)
        and C(allow_more_present).
      - If C(strict) is specified, values are tested for equality, and changes always
        result in updating or restarting. If C(ignore) is specified, changes are ignored.
      - C(allow_more_present) is allowed only for lists, sets and dicts. If it is
        specified for lists or sets, the container will only be updated or restarted if
        the module option contains a value which is not present in the container's
        options. If the option is specified for a dict, the container will only be updated
        or restarted if the module option contains a key which isn't present in the
        container's option, or if the value of a key present differs.
      - The wildcard option C(*) can be used to set one of the default values C(strict)