Remove some bogus duplication in Sell (caused the double-sell bug).

OpenRA.Mods.RA/Activities/MakeAnimation.cs

@@ -37,7 +37,9 @@ namespace OpenRA.Mods.RA.Activities
 				started = true;
 				if (Reversed)
 				{
-					foreach (var s in self.Info.Traits.Get<BuildingInfo>().SellSounds)
+					var bi = self.Info.Traits.GetOrDefault<BuildingInfo>();
+					if (bi != null)
+						foreach (var s in bi.SellSounds)
 							Sound.PlayToPlayer(self.Owner, s, self.CenterLocation);
 					
 					// PlayCustomAnim is required to stop a frame of the normal state after the anim completes

OpenRA.Mods.RA/Render/RenderBuilding.cs

@@ -32,7 +32,7 @@ namespace OpenRA.Mods.RA.Render
 		}
 	}
 
-	public class RenderBuilding : RenderSimple, INotifyDamage, INotifySold, IRenderModifier
+	public class RenderBuilding : RenderSimple, INotifyDamage, IRenderModifier
 	{
 		readonly RenderBuildingInfo Info;
 		
@@ -112,16 +112,5 @@ namespace OpenRA.Mods.RA.Render
 			else if (e.DamageState < DamageState.Heavy)
 				anim.ReplaceAnim("idle");
 		}
-
-		public virtual void Selling( Actor self )
-		{
-			if( Info.HasMakeAnimation )
-				anim.PlayBackwardsThen( "make", null );
-			
-			foreach (var s in self.Info.Traits.Get<BuildingInfo>().SellSounds)
-					Sound.PlayToPlayer(self.Owner, s, self.CenterLocation);
-		}
-
-		public void Sold(Actor self) {}
 	}
 }

OpenRA.Mods.RA/Render/RenderBuildingWarFactory.cs

@@ -87,10 +87,11 @@ namespace OpenRA.Mods.RA.Render
 			roof.PlayThen(NormalizeSequence(self, "build-top"), () => { isOpen = true; openExit = exit; });
 		}
 
-		public override void Selling( Actor self )
+		public void Selling(Actor self)
 		{
 			self.Trait<RenderSimple>().anims.Remove("roof");
-			base.Selling(self);
-		}
+		}
+		
+		public void Sold(Actor self) { }
 	}
 }