Comment unused variables.

synapse/storage/stream.py

@@ -139,8 +139,8 @@ class StreamStore(SQLBaseStore):
             limit = MAX_STREAM_SIZE
 
         # From and to keys should be integers from ordering.
-        from_id = _StreamToken.parse_stream_token(from_key)
-        to_id = _StreamToken.parse_stream_token(to_key)
+        # from_id = _StreamToken.parse_stream_token(from_key)
+        # to_id = _StreamToken.parse_stream_token(to_key)
 
         if from_key == to_key:
             return defer.succeed(([], to_key))