[TS-58]<enhance>: default compressMsgSize to 512k instead of -1

src/common/src/tglobal.c

@@ -74,7 +74,7 @@ int32_t tsMaxBinaryDisplayWidth = 30;
  * -1: all data are not compressed
  * other values: if the message payload size is greater than the tsCompressMsgSize, the message will be compressed.
  */
-int32_t tsCompressMsgSize = -1;
+int32_t tsCompressMsgSize = 512 * 1024;
 
 // client
 int32_t tsMaxSQLStringLen = TSDB_MAX_ALLOWED_SQL_LEN;