[BUG]DDL SQL parse out of index problem

[lvfeifei08]

Environment

• Ptubes version: 1.0.0

• Operating System version: Linux

• Java version: 1.8

Steps to reproduce this issue

Execute SQL "alter table table_1" to clean up table holes.

Expected Behavior

Reader parse sql "alter table table_1" successfully and then fetch new schema from MySQL.

Actual Behavior

Reader will occurred error when parsing sql "alter table table_1" and skip this DDL event.

[myksl]

hi, lvfei,I saw this problem, I tried to follow your process and found that it can be reproduced, it is a bug, we need to fix it