fix: V5 원상태 복구

Author: JunbeomKoreaUniv

ontime-back/src/main/resources/db/migration/V5__change_field_accesstoken_length.sql

@@ -1,2 +1,2 @@
-ALTER TABLE `user`
-    MODIFY COLUMN `access_token` TEXT;
+ALTER TABLE user
+    MODIFY COLUMN access_token TEXT;