fixed erroneous warning about wrong nights on hotel assignments page

People kept seeing the warning message, "This attendee has requested setup/teardown and you are assigning them to a regular room, wnich will automatically decline their request to help with setup/teardown."

Which is fine except that they'd see it even when it didn't apply!  The backend did the correct thing, so if you ignored the warning it wouldn't mess anything up, which is good.  This pull request makes the warning only happen when it should.
This special-casing of "Tue" is no longer necessary since as of this year the code properly handles the "night before and two nights before" automatically based on ``EPOCH``.  I had just forgotten to take out this special-casing which didn't matter anyway since none of the pre-created rooms are for Tuesday night anyway.