Allow empty watches in Redis.transaction()

Author: Suor

redis/client.py

@@ -240,7 +240,8 @@ def transaction(self, func, *watches, **kwargs):
         with self.pipeline(True, shard_hint) as pipe:
             while 1:
                 try:
-                    pipe.watch(*watches)
+                    if watches:
+                        pipe.watch(*watches)
                     func(pipe)
                     return pipe.execute()
                 except WatchError: