Fix foreign key violation on irreversible_data

3fc63536 Introduced a check to fix a possible deadlock.

This however caused the trigger to not properly handle current block_num, which was skipped because of early return. The block was not pushed to the database and this later lead to foreign key violation when updating irreversible_data table.

To fix the issue, move the check at the end of the trigger function, after the current block is handled.

No new test was added, as existing replay_restarts_with_app test catches this.

Closes #223 (closed)