Remove unused variables from Map.SavePreview.

OpenRA.Game/Map/Map.cs

@@ -696,7 +696,6 @@ namespace OpenRA
 
 		public byte[] SavePreview()
 		{
-			var tileset = Rules.TileSet;
 			var actorTypes = Rules.Actors.Values.Where(a => a.HasTraitInfo<IMapPreviewSignatureInfo>());
 			var actors = ActorDefinitions.Where(a => actorTypes.Where(ai => ai.Name == a.Value.Value).Any());
 			var positions = new List<(MPos Position, Color Color)>();
@@ -716,8 +715,6 @@ namespace OpenRA
 			foreach (var worldimpsi in worldimpsis)
 				worldimpsi.PopulateMapPreviewSignatureCells(this, worldActorInfo, null, positions);
 
-			using (var stream = new MemoryStream())
-			{
 			var isRectangularIsometric = Grid.Type == MapGridType.RectangularIsometric;
 
 			// Fudge the heightmap offset by adding as much extra as we need / can.
@@ -786,7 +783,6 @@ namespace OpenRA
 			var png = new Png(minimapData, bitmapWidth, height);
 			return png.Save();
 		}
-		}
 
 		public bool Contains(CPos cell)
 		{