Fix non-matching defaults. (#5452) (#5454)

(cherry picked from commit f84a9bf932)

plugins/modules/cloud/rackspace/rax.py

@@ -81,17 +81,20 @@ options:
     default: 'no'
   extra_client_args:
     type: dict
+    default: {}
     description:
       - A hash of key/value pairs to be used when creating the cloudservers
         client. This is considered an advanced option, use it wisely and
         with caution.
   extra_create_args:
     type: dict
+    default: {}
     description:
       - A hash of key/value pairs to be used when creating a new server.
         This is considered an advanced option, use it wisely and with caution.
   files:
     type: dict
+    default: {}
     description:
       - Files to insert into the instance. remotefilename:localcontent
   flavor:
@@ -123,6 +126,7 @@ options:
       - keypair
   meta:
     type: dict
+    default: {}
     description:
       - A hash of metadata to associate with the instance
   name: