Fix copypaste errors in access rule command

Access rules are access rules, not application credentials.

Change-Id: I74d05f11ec186283e5a86d92dcbfe4eb24130eee

Author: cmurphy

openstackclient/identity/v3/access_rule.py

@@ -38,7 +38,7 @@ def get_parser(self, prog_name):
             'access_rule',
             metavar='<access-rule>',
             nargs="+",
-            help=_('Application credentials(s) to delete (name or ID)'),
+            help=_('Access rule(s) to delete (name or ID)'),
         )
         return parser
 
@@ -104,7 +104,7 @@ def get_parser(self, prog_name):
         parser.add_argument(
             'access_rule',
             metavar='<access-rule>',
-            help=_('Application credential to display (name or ID)'),
+            help=_('Access rule to display (name or ID)'),
         )
         return parser