fix dumb crash in minimap -- actors outside the map accessed memory that wasnt part of the bitmap.

OpenRA.Game/Graphics/Minimap.cs

@@ -124,6 +124,7 @@ namespace OpenRA.Graphics
 				{
 					var color = t.Trait.RadarSignatureColor(t.Actor);
 					foreach (var cell in t.Trait.RadarSignatureCells(t.Actor))
+						if (world.Map.IsInMap(cell))
 							*(c + ((cell.Y - world.Map.TopLeft.Y) * bitmapData.Stride >> 2) + cell.X - world.Map.TopLeft.X) = color.ToArgb();
 				}
 			}