v0.5.0: fixed imp spawning ontop of enemies

core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/mobs/npcs/Imp.java

@@ -183,7 +183,7 @@ public class Imp extends NPC {
 				Imp npc = new Imp();
 				do {
 					npc.pos = level.randomRespawnCell();
-				} while (npc.pos == -1 || level.heaps.get( npc.pos ) != null);
+				} while (npc.pos == -1 || level.heaps.get( npc.pos ) != null || level.findMob( npc.pos ) != null);
 				level.mobs.add( npc );
 				
 				spawned = true;