[TD-12014]<fix>: taosshell crash when apply arithmetic operation with select now

src/client/src/tscSQLParser.c

@@ -4694,6 +4694,11 @@ static int32_t validateSQLExprItem(SSqlCmd* pCmd, tSqlExpr* pExpr,
       return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg3);
     }
 
+    //now allowing now +/- value in select expr
+    if (pExpr->tokenId == TK_TIMESTAMP) {
+      return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg3);
+    }
+
     if (pExpr->type == SQL_NODE_VALUE) {
       *type = SQLEXPR_TYPE_VALUE;
     }