[TD-2337]/<fix>: fix *Ref is not there* when unable to establish connection

src/client/src/tscSql.c

@@ -292,6 +292,7 @@ void taos_close(TAOS *taos) {
   pObj->signature = NULL;
   taosTmrStopA(&(pObj->pTimer));
 
+  if (pObj->hbrid > 0) {
     SSqlObj* pHb = (SSqlObj*)taosAcquireRef(tscObjRef, pObj->hbrid);
     if (pHb != NULL) {
       if (pHb->rpcRid > 0) {  // wait for rsp from dnode
@@ -303,6 +304,7 @@ void taos_close(TAOS *taos) {
       taos_free_result(pHb);
       taosReleaseRef(tscObjRef, pHb->self);
     }
+  }
 
   int32_t ref = T_REF_DEC(pObj);
   assert(ref >= 0);