Reset stream position after TryParseSound failures

OpenRA.Game/FileFormats/WavLoader.cs

@@ -181,6 +181,7 @@ namespace OpenRA.FileFormats
 		{
 			rawData = null;
 			channels = sampleBits = sampleRate = 0;
+			var position = stream.Position;
 
 			try
 			{
@@ -197,6 +198,10 @@ namespace OpenRA.FileFormats
 				Log.Write("sound", e.ToString());
 				return false;
 			}
+			finally
+			{
+				stream.Position = position;
+			}
 
 			rawData = RawOutput;
 			channels = Channels;