Protection from shape changers via wizintrinsics

Setting protection from shape changers via wizintrinsics
caused a sanity error on the next turn, if any monsters affected
by it were in changed shaped on the level.

Call rescham after setting the timeout, so the monsters will
immediately revert to their own form.

src/cmd.c

@@ -2129,6 +2129,8 @@ wiz_intrinsic(void)
             /* this has to be after incr_timeout() */
             if (p == LEVITATION || p == FLYING)
                 float_vs_flight();
+            else if (p == PROT_FROM_SHAPE_CHANGERS)
+                rescham();
         }
         if (n >= 1)
             free((genericptr_t) pick_list);