replace groovy code with ability in card script

release/Magarena/scripts/Wojek_Halberdiers.groovy

@@ -1,19 +0,0 @@
-[
-    new MagicBattalionTrigger() {
-        @Override
-        public MagicEvent executeTrigger(final MagicGame game, final MagicPermanent permanent, final MagicPermanent attacker) {
-            return new MagicEvent(
-                permanent,
-                this,
-                "SN gains first strike until end of turn."
-            );
-        }
-        @Override
-        public void executeEvent(final MagicGame game, final MagicEvent event) {
-            game.doAction(new MagicGainAbilityAction(
-                event.getPermanent(),
-                MagicAbility.FirstStrike
-            ));
-        }
-    }
-]

release/Magarena/scripts/Wojek_Halberdiers.txt

@@ -7,5 +7,5 @@ type=Creature
 subtype=Human,Soldier
 cost={R}{W}
 pt=3/2
+ability=battalion effect SN gains first strike until end of turn.
 timing=main
-requires_groovy_code