fix sql symbol error (#5462)

sql/dolphinscheduler_mysql.sql

@@ -352,7 +352,7 @@ CREATE TABLE `t_ds_datasource` (
   `create_time` datetime NOT NULL COMMENT 'create time',
   `update_time` datetime DEFAULT NULL COMMENT 'update time',
   PRIMARY KEY (`id`),
-  UNIQUE KEY `t_ds_datasource_name_UN` ('name', 'type')
+  UNIQUE KEY `t_ds_datasource_name_UN` (`name`, `type`)
 ) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;
 
 -- ----------------------------

sql/upgrade/1.4.0_schema/mysql/dolphinscheduler_ddl.sql

@@ -307,7 +307,7 @@ BEGIN
                      AND TABLE_SCHEMA=(SELECT DATABASE())
                      AND COLUMN_NAME ='t_ds_datasource_name_UN')
     THEN
-        ALTER TABLE t_ds_datasource ADD UNIQUE KEY `t_ds_datasource_name_UN` ('name', 'type');
+        ALTER TABLE t_ds_datasource ADD UNIQUE KEY `t_ds_datasource_name_UN` (`name`, `type`);
     END IF;
 END;