##### SUMMARY
When using the `host-header` condition for a load balancer rule if there are multiple values for the host header ansible fails to apply the changes with broken json output.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
elbv2

##### ANSIBLE VERSION
```
ansible 2.10.0.dev0
  config file = None
  configured module search path = [u'/home/mjmayer/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
  ansible python module location = /home/mjmayer/repos/ansible/lib/ansible
  executable location = /home/mjmayer/repos/ansible/bin/ansible
  python version = 2.7.15+ (default, Oct  7 2019, 17:39:04) [GCC 7.4.0]

```

##### CONFIGURATION
```
```

##### OS / ENVIRONMENT
Mint 19.2 / Ubuntu 18.04

##### STEPS TO REPRODUCE

```yaml
  - name: add a rule that uses the host header condition to the listener
    elb_application_lb:
      name: "{{ alb_name }}"
      subnets: "{{ alb_subnets }}"
      security_groups: "{{ sec_group.group_id }}"
      state: present
      purge_rules: no
      listeners:
        - Protocol: HTTP
          Port: 80
          DefaultActions:
            - Type: forward
              TargetGroupName: "{{ tg_name }}"
          Rules:
            - Conditions:
                - Field: host-header
                  Values:
                    - 'local.mydomain.com'
              Priority: '3'
              Actions:
                - TargetGroupName: "{{ tg_name }}"
                  Type: forward
      <<: *aws_connection_info
    register: alb

  - assert:
      that:
        - alb.changed
        - alb.listeners[0].rules|length == 4

  - name: test replacing the rule that uses the host header condition with multiple host header conditions
    elb_application_lb:
      name: "{{ alb_name }}"
      subnets: "{{ alb_subnets }}"
      security_groups: "{{ sec_group.group_id }}"
      purge_rules: no
      state: present
      listeners:
        - Protocol: HTTP
          Port: 80
          DefaultActions:
            - Type: forward
              TargetGroupName: "{{ tg_name }}"
          Rules:
            - Conditions:
                - Field: host-header
                  Values:
                    - 'local.mydomain.com'
                    - 'alternate.mydomain.com'
              Priority: '3'
              Actions:
                - TargetGroupName: "{{ tg_name }}"
                  Type: forward
      <<: *aws_connection_info
    register: alb
```
##### EXPECTED RESULTS
The second application of `elb_application_lb` should succeed and add the second host-header.


##### ACTUAL RESULTS
Ansible prints invalid json to the screen with the following error.
```paste below
Module invocation had junk after the JSON data
```

listeners_obj = ELBListeners(elb_obj.connection, elb_obj.module, elb_obj.elb['LoadBalancerArn'])
    listeners_to_add, listeners_to_modify, listeners_to_delete = listeners_obj.compare_listeners()
    
    for listener_to_delete in listeners_to_delete:
        listener_obj = ELBListener(elb_obj.connection, elb_obj.module, listener_to_delete, elb_obj.elb['LoadBalancerArn'])
        listener_obj.delete()
        listeners_obj.changed = True
    
    for listener_to_add in listeners_to_add:
        listener_obj = ELBListener(elb_obj.connection, elb_obj.module, listener_to_add, elb_obj.elb['LoadBalancerArn'])
        listener_obj.add()
        listeners_obj.changed = True
    
    for listener_to_modify in listeners_to_modify:
        listener_obj = ELBListener(elb_obj.connection, elb_obj.module, listener_to_modify, elb_obj.elb['LoadBalancerArn'])
        listener_obj.modify()
        listeners_obj.changed = True
    
    if listeners_obj.changed:
        elb_obj.changed = True
    
    for listener in listeners_obj.listeners:
        if 'Rules' in listener:
            rules_obj = ELBListenerRules(elb_obj.connection, elb_obj.module, elb_obj.elb['LoadBalancerArn'], listener['Rules'], listener['Port'])
            rules_to_add, rules_to_modify, rules_to_delete = rules_obj.compare_rules()
            
            if elb_obj.module.params['purge_rules']:
                for rule in rules_to_delete:
                    rule_obj = ELBListenerRule(elb_obj.connection, elb_obj.module, {'RuleArn': rule}, rules_obj.listener_arn)