Merge pull request #9759 from atlimit8/ActorsHavingTrait

Add ActorsHavingTrait<TTrait>()

OpenRA.Mods.Common/Scripting/Properties/PlayerProperties.cs

@@ -55,7 +55,7 @@ namespace OpenRA.Mods.Common.Scripting
 		[Desc("Returns an array of actors representing all ground attack units of this player.")]
 		public Actor[] GetGroundAttackers()
 		{
-			return Player.World.ActorsWithTrait<AttackBase>().Select(a => a.Actor)
+			return Player.World.ActorsHavingTrait<AttackBase>()
 				.Where(a => a.Owner == Player && !a.IsDead && a.IsInWorld && a.Info.HasTraitInfo<MobileInfo>())
 				.ToArray();
 		}