fdo#73281: Write an export test for strike-through text attribute.

Change-Id: Ib9cffac17a8f2e0bb016952ae5dd1b00bd4fc9f9
fdo#73281: Why!?

This restriction makes absolutely no sense.  It was likely someone's
temporarily hack that was totally forgotten in the past 10 years...

Not to mention removing this fixes my bug.

Change-Id: I7394cccdc9fe486fda6cdd9b7eaf98fd291895a9