Fix RotationPaletteEffect tileset validity check

If Tilesets was empty but ExcludeTilesets was not, it would always return false even though that combination is supposed to mean only the excluded tileset(s) is/are not valid for this effect.

OpenRA.Mods.Common/Traits/PaletteEffects/RotationPaletteEffect.cs

@@ -66,6 +66,9 @@ namespace OpenRA.Mods.Common.Traits
 			if (info.Tilesets.Count == 0 && info.ExcludeTilesets.Count == 0)
 				return true;
 
+			if (info.Tilesets.Count == 0 && !info.ExcludeTilesets.Contains(tilesetId))
+				return true;
+
 			return info.Tilesets.Contains(tilesetId) && !info.ExcludeTilesets.Contains(tilesetId);
 		}