Feat actiontech/dms-ee/issues/125: add nil check

Author: wangyue

sqle/driver/v2/util.go

@@ -247,6 +247,9 @@ func ConvertProtoSQLOpsResponseToDriver(sqlOps *protoV2.GetSQLOpResponse) ([]*SQ
 				Op:     op,
 				Object: object,
 			})
+			if sqlOp.GetSql() == nil {
+				return nil, fmt.Errorf("sql info should not be nil")
+			}
 			sqlOpList = append(sqlOpList, &SQLObjectOps{
 				ObjectOps: objectOpList,
 				Sql:       SQLInfo{Sql: sqlOp.GetSql().GetSql()},