fix bug: get deleted db when autocommit=0

[ouyuanning]

What type of PR is this?

• [ ] API-change
• [x] BUG
• [ ] Improvement
• [ ] Documentation
• [ ] Feature
• [ ] Test and CI
• [ ] Code Refactoring

Which issue(s) this PR fixes:

issue #14878

What this PR does / why we need it:

fix bug: get deleted db when autocommit=0 bug repro:

create database db1;
set autocommit=0;
drop database db1;
show databases;  // return db list will contains db1