Use ansible.module_utils.six instead of six

This patch is needed to pass Automation Hub tests.

roles/ipareplica/library/ipareplica_add_to_ipaservers.py

@@ -64,7 +64,6 @@ RETURN = '''
 '''
 
 import os
-import six
 
 from ansible.module_utils.basic import AnsibleModule
 from ansible.module_utils.ansible_ipa_replica import (
@@ -73,6 +72,8 @@ from ansible.module_utils.ansible_ipa_replica import (
     gen_remote_api, api
 )
 
+from ansible.module_utils import six
+
 if six.PY3:
     unicode = str