Change MigrateForumTest to use forum test fixture

The last submitted patch, 2: 3350511-2.patch, failed testing. View results →

The fixture change was to add 'Upload' so that needed a change in the Upgrade test as well.

This is isolated to forum tests/fixtures so makes sense to me.

Committed 48e0549 and pushed to 10.1.x. Thanks!

Automatically closed - issue fixed for 2 weeks with no activity.