Commit d25d33ff cleaned up some of the tag face code. However, for the
face notmuch-tag-deleted it used the test
((class color) (supports :strike-through))
to decide whether to use red strikethrough or inverse-video (emacs in
a terminal typically doesn't support red strikethrough, but in X it does).
However, it seems that test often returns true even though red
strikethrough is not supported. This breaks the tag update code -- the
wrong thing is displayed to the user.
Thus we make the test explicitly more specific, changing the test to
((class color) (supports :strike-through "red"))
51d27e0855
