Remove door crush damage for polymorphed critters

[Spy_Guy]

This was all caused by a bug with how doors check for living things for the safety. Critters didn't block the closing like humans would.
On one hand, this is kind of realistic since critters are smaller. On the other hand, it sucks to be taken out of the round by murderdoors every time.

There's still a very small 1% chance that the door will close, regardless of the sensor, same for everyone.