make secondary user groups optional

Author: Colin Hoglund

tasks/main.yml

@@ -14,7 +14,8 @@
   user:
     name: "{{item.username}}"
     group: "{{item.username if users_create_per_user_group else users_group}}"
-    groups: "{{item.groups | join(',')}}"
+    # empty string removes user from all secondary groups
+    groups: "{{item.groups | join(',') if 'groups' in item else ''}}"
     shell: "{{item.shell if item.shell is defined else users_default_shell}}"
     password: "{{item.password if item.password is defined else '!'}}"
     comment: "{{item.name}}"