Disable XDC for dq

Author: dcherednik

ydb/library/yql/providers/dq/config/config.proto

@@ -25,7 +25,7 @@ message TDqConfig {
         optional uint64 MessagePendingTimeoutMs = 15 [default = 5000];
         optional uint64 MessagePendingSize = 16 [default = 18446744073709551615];
         optional uint32 MaxSerializedEventSize = 17 [default = 67108000];
-        optional bool EnableExternalDataChannel = 27 [default = true];
+        optional bool EnableExternalDataChannel = 27 [default = false];
 
         // Scheduler
         optional uint64 ResolutionMicroseconds = 18 [default = 1024];