v0.2.3e: corrected error in new pirahna logic

src/com/shatteredpixel/shatteredpixeldungeon/actors/mobs/Piranha.java

@@ -59,6 +59,7 @@ public class Piranha extends Mob {
 		} else {
 			//this causes pirahna to move away when a door is closed on them.
 			Dungeon.level.updateFieldOfView( this );
+			enemy = chooseEnemy();
 			if (state == this.HUNTING && !(enemy.isAlive() && Level.fieldOfView[enemy.pos] && enemy.invisible <= 0)){
 				state = this.WANDERING;
 				int oldPos = pos;