fix: because lock is not release, drop cutover sentry table is hanged

[lmtwga]

Related issue: https://github.com/github/gh-ost/issues/1171

[lmtwga]

@dm-2 Please review when you have time. Thank you very much!

[lmtwga]

@dm-2 @timvaillancourt Please review when you have time. Thank you very much!

[dm-2]

The problem and the fix make sense to me :+1:

@timvaillancourt would you mind taking a look as well? 🙇 Your thoughts would be much appreciated, given that it's such a critical section of code!

[gtowey-air]

Hey @dm-2; I just got hit with this bug as well and I would love to get this or some related fix merged -- would you mind if I took a look and did some testing on this PR to validate?

[gtowey-air]

@rashiq @dm-2 I've tested this PR and it looks like it fixes the problem. I recommend that we go ahead and merge this!

[timvaillancourt]

@timvaillancourt would you mind taking a look as well?

Sorry for the delay, this LGTM 👍

[gtowey-air]

@rashiq Thanks for the approval! Would you be able to merge this?

[rashiq]

@gtowey-air Hey! (also nice to see you again!) - sorry for the delay, merging now