<!--- 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)
```

description:
          - 'Time between running the check. (default: 30s)'
        type: str
      timeout:
        description:
          - 'Maximum time to allow one check to run. (default: 30s)'
        type: str
      retries:
        description:
          - 'Consecutive failures needed to report unhealthy. It accept integer value. (default: 3)'
        type: int
      start_period:
        description:
          - 'Start period for the container to initialize before starting health-retries countdown. (default: 0s)'
        type: str
    version_added: "2.8"
  hostname:
    description:
      - Container hostname.
    type: str
  ignore_image:
    description:
      - When C(state) is I(present) or I(started) the module compares the configuration of an existing
        container to requested configuration. The evaluation includes the image version. If
        the image version in the registry does not match the container, the container will be
        recreated. Stop this behavior by setting C(ignore_image) to I(True).
      - I(Warning:) This option is ignored if C(image) or C(*) is used for the C(comparisons) option.
    type: bool
    default: no
    version_added: "2.2"