fix: ignore Ref is not there to save true error

src/client/src/tscSql.c

@@ -205,7 +205,9 @@ TAOS *taos_connect_internal(const char *ip, const char *user, const char *pass,
       } else {
         printf("connect failed, reason: %s.\n\n", tstrerror(terrno));
       }
+      int32_t lastError = terrno;
       taos_free_result(pSql);
+      if (terrno != lastError) terrno = lastError;
       taos_close(pObj);
       return NULL;
     }