reference table not exists when add foreign key statement is the first statement that table in syncer

[GMHDBJD]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. What did you do? If possible, provide a recipe for reproducing the error.

start task
alter table tb1 add constraint foreign key (a) references tb2(a);

2. What did you expect to see?
   worker runs well
3. What did you see instead?

{
                                "ErrCode": 44006,
                                "ErrClass": "schema-tracker",
                                "ErrScope": "internal",
                                "ErrLevel": "high",
                                "Message": "startLocation: [position: (mysql-bin.000001, 987), gtid-set: 90ef7875-f829-11ea-a36c-0242ac110002:1-4], endLocation: [position: (mysql-bin.000001, 1154), gtid-set: 90ef7875-f829-11ea-a36c-0242ac110002:1-5]: cannot track DDL: ALTER TABLE `handle_error`.`tb1` ADD CONSTRAINT FOREIGN KEY (`a`) REFERENCES `handle_error`.`ta`(`a`)",
                                "RawCause": "[schema:1146]Table 'handle_error.ta' doesn't exist",
                                "Workaround": ""
}

4. Versions of the cluster

   • DM version (run dmctl -V or dm-worker -V or dm-master -V):

     master