Update regex to also match colorless healthbar instances

src/main/java/com/gmail/nossr50/util/MobHealthbarUtils.java

@@ -27,7 +27,7 @@ public final class MobHealthbarUtils {
         EntityDamageEvent lastDamageCause = player.getLastDamageCause();
         String replaceString = lastDamageCause instanceof EntityDamageByEntityEvent ? StringUtils.getPrettyEntityTypeString(((EntityDamageByEntityEvent) lastDamageCause).getDamager().getType()) : "a mob";
 
-        return deathMessage.replaceAll("(?:\u00A7(?:[0-9A-FK-ORa-fk-or]){1}(?:[\u2764\u25A0]{1,10})){1,2}", replaceString);
+        return deathMessage.replaceAll("(?:(\u00A7(?:[0-9A-FK-ORa-fk-or]))*(?:[\u2764\u25A0]{1,10})){1,2}", replaceString);
     }
 
     /**