fix xmltv generation with missing episode metadata (#402)

CHANGELOG.md

@@ -16,6 +16,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Fixed
 - Add downsampling to support transcoding 10-bit HEVC content with the h264_vaapi encoder
 - Fix updating statistics when media items are replaced
+- Fix XMLTV generation when scheduled episode is missing metadata
 
 ## [0.0.62-alpha] - 2021-10-05
 ### Added

ErsatzTV.Core/Iptv/ChannelGuide.cs

@@ -202,7 +202,7 @@ namespace ErsatzTV.Core.Iptv
                         {
                             int s = Optional(episode.Season?.SeasonNumber).IfNone(-1);
                             // TODO: multi-episode?
-                            int e = episode.EpisodeMetadata.Head().EpisodeNumber;
+                            int e = episode.EpisodeMetadata.HeadOrNone().Match(em => em.EpisodeNumber, -1);
                             if (s >= 0 && e > 0)
                             {
                                 xml.WriteStartElement("episode-num");