[Git 1.5] Bug with new Dirty Fighting/backstab

[Mordy]

This is just a code diving bug detection but the new backstab that has chance to pin targets doesn't correctly check pin resistance (it calls canBe("pinned") instead of canBe("pin") ) so pinning immunity probably doesn't work against it as it should.

[Razakai]

You caught me just as I was doing roguestuff so added this fix in, thanks.