Update MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs

Co-authored-by: Cody Robibero <cody@robibe.ro>

MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs

@@ -43,7 +43,7 @@ namespace MediaBrowser.Controller.MediaEncoding
         /// The level validation regex.
         /// This regular expression matches strings representing a double.
         /// </summary>
-        public const string LevelValidationRegex = @"-?\d+(?:\.\d+)?";
+        public const string LevelValidationRegex = @"-?[0-9]+(?:\.[0-9]+)?";
 
         private const string _defaultMjpegEncoder = "mjpeg";