Iron curtain power implementation; Remove AutoActivate attribute to be part of the GPS implementation

OpenRa.Game/GameRules/SupportPowerInfo.cs

@@ -17,6 +17,5 @@ namespace OpenRa.Game.GameRules
 		public readonly int TechLevel = -1;
 		public readonly bool GivenAuto = true;
 		public readonly string Impl = null;
-		public readonly bool AutoActivate = false;
 	}
 }