give centaur back the no-ep loss special.

I think even though centaurs are like horses that can go for long distances,
they get tired in the end, horses have died on gallopping for hours and forced
to it, so it's more appropriate that they'd lose 1 ep instead of keeping them
infinitely. Tinmen, skeletons, zombies and undeads usually are non-living and
don't have metabolism and thus they'd have bigger reason to get the infinite
movement, _IF_ they get it. The wizards have made decision, and that's how
things are, but you can always give feedback about tunes of course. This is my
feedback.