[data][RemoteDataSource] Add missing decoding on received value in _prepare

beat/backend/python/data.py

@@ -717,7 +717,7 @@ class RemoteDataSource(DataSource):
         self.socket.send_string('ifo', zmq.SNDMORE)
         self.socket.send_string(self.input_name)
 
-        answer = self.socket.recv()
+        answer = self.socket.recv().decode('utf-8')
         logger.debug('recv: %s', answer)
 
         if answer == 'err':