When polymorphed into an iron golem (or gremlin with 2/3 chance),
triggering a rust trap would give "a gush of water hits <you or some
body part>" and then give a second "a gush of water hits you" when
dealing with golem or gremlin effects. That made it seem as if the
trap was hitting twice. This removes the redundant messages. (Rust
trap against monster iron golem or gremlin didn't have them.)