Fixed #25123 -- Corrected makemessages --extension help text

        parser.add_argument('--all', '-a', action='store_true', dest='all',

            default=False, help='Updates the message files for all existing locales.')

        parser.add_argument('--extension', '-e', dest='extensions',

            help='The file extension(s) to examine (default: "html,txt", or "js" '

            help='The file extension(s) to examine (default: "html,txt,py", or "js" '

                 'if the domain is "djangojs"). Separate multiple extensions with '

                 'commas, or use -e multiple times.',

            action='append')