fixed MysqlAdapter check in Utf8mb4Fix migration

[GustavoPeixoto]

This PR is related to #441.

In MySQL databases, the text columns data and failure_message should have a length limit of MEDIUM, but they do not. This is because the if condition in Utf8mb4Fix will never be satisfied, since the MysqlAdapter will be wrapped inside the CakeAdapter.

This PR fixes the if condition, getting the adapter inside the wrapper before checking it's instance.

[dereuromark]

Does removing and rerunning this migrations work for u? Or any issues?

[dereuromark]

Given that this is quite old of a migration it does seem ir could be a good idea to have new migration.

[GustavoPeixoto]

Does removing and rerunning this migrations work for u? Or any issues?

Doesn't work because job_type was renamed to job_task by MigrationQueueRename.

The first part of the migration doesn't need to rerun, only the part inside the if.

So i think, its a better idea to write a new migration, only with the part that matters.

[GustavoPeixoto]

Fixed it by creating DataColumnLength.

I tested it, and it works. It doesn't undo any changes made by previous migrations.

[GustavoPeixoto]

Will 6.9.3 be released?

[dereuromark]

https://github.com/dereuromark/cakephp-queue/releases/tag/6.9.3