refactor checkpoint

source/dnode/mnode/impl/src/mndDef.c

@@ -76,11 +76,11 @@ int32_t tEncodeSStreamObj(SEncoder *pEncoder, const SStreamObj *pObj) {
 
   if (tEncodeSSchemaWrapper(pEncoder, &pObj->outputSchema) < 0) return -1;
 
-  // 3.0.20
+  // 3.0.20 ver =2
   if (tEncodeI64(pEncoder, pObj->checkpointFreq) < 0) return -1;
   if (tEncodeI8(pEncoder, pObj->igCheckUpdate) < 0) return -1;
 
-  // 3.0.50
+  // 3.0.50 ver = 3
   if (tEncodeI64(pEncoder, pObj->checkpointId) < 0) return -1;
 
   tEndEncode(pEncoder);