Change help string for sopds_server command

    help = 'HTTP/OPDS built-in server'

    def add_arguments(self, parser):

        parser.add_argument('command', help='Start, stop or restart server')

        parser.add_argument('command', help='Use [ start | stop | restart ]')

        #parser.add_argument('stop',help='Start server')

        parser.add_argument('--host',action='store', dest='host', default="0.0.0.0", help='Set server binding address')

        parser.add_argument('--port',action='store', dest='port', default=8001, help='Ser server port')