add OldManNPC dialogue setup

src/de/miaurizius/jgame2d/entity/npc/OldManNPC.java

@@ -68,6 +68,7 @@ public class OldManNPC extends Entity {
         right1 = initEntitySprites("npc/oldman_right_1");
         right2 = initEntitySprites("npc/oldman_right_2");
     }
+    @Override
     public void setDialogue() {
         dialogue[0][0] = "Hello, lad.";
         dialogue[0][1] = "So you've come to this island to \nfind the treasure?";