Fix DamageModifiers

OpenRA.Game/Traits/TraitsInterfaces.cs

@@ -205,7 +205,7 @@ namespace OpenRA.Traits
 	}
 
 	public interface IRenderModifier { IEnumerable<IRenderable> ModifyRender(Actor self, WorldRenderer wr, IEnumerable<IRenderable> r); }
-	public interface IDamageModifier { int GetDamageModifier(Actor attacker, DamageWarhead warhead); }
+	public interface IDamageModifier { int GetDamageModifier(Actor attacker, IWarhead warhead); }
 	public interface ISpeedModifier { int GetSpeedModifier(); }
 	public interface IFirepowerModifier { int GetFirepowerModifier(); }
 	public interface IReloadModifier { int GetReloadModifier(); }