add dvbsub as not text

MediaBrowser.Model/Entities/MediaStream.cs

@@ -195,6 +195,7 @@ namespace MediaBrowser.Model.Entities
 
             return StringHelper.IndexOfIgnoreCase(codec, "pgs") == -1 &&
                    StringHelper.IndexOfIgnoreCase(codec, "dvd") == -1 &&
+                   StringHelper.IndexOfIgnoreCase(codec, "dvbsub") == -1 &&
                    !StringHelper.EqualsIgnoreCase(codec, "sub");
         }