chore: set err code when rpcConn error

src/client/src/tscServer.c

@@ -663,9 +663,6 @@ void tscProcessMsgFromServer(SRpcMsg *rpcMsg, SRpcEpSet *pEpSet) {
         memcpy(pRes->pRsp, rpcMsg->pCont, pRes->rspLen);
       }
     } else {
-      if (!rpcMsg->pCont && TSDB_CODE_SUCCESS == pRes->code) {
-        pRes->code = TSDB_CODE_RPC_UNEXPECTED_RESPONSE;
-      }
       tfree(pRes->pRsp);
     }
 

src/rpc/src/rpcMain.c

@@ -1535,7 +1535,7 @@ static void rpcProcessConnError(void *param, void *id) {
   if (pContext->numOfTry >= pContext->epSet.numOfEps || pContext->msgType == TSDB_MSG_TYPE_FETCH) {
     rpcMsg.msgType = pContext->msgType + 1;
     rpcMsg.ahandle = pContext->ahandle;
-    rpcMsg.code = pContext->code;
+    rpcMsg.code = pContext->code != TSDB_CODE_SUCCESS ? pContext->code : TSDB_CODE_RPC_TOO_SLOW;
     rpcMsg.pCont = NULL;
     rpcMsg.contLen = 0;