Fixed: Grab/Import fields for Discord notifications being duplicated

src/NzbDrone.Core/Notifications/Discord/Discord.cs

@@ -138,7 +138,7 @@ namespace NzbDrone.Core.Notifications.Discord
             {
                 embed.Thumbnail = new DiscordImage
                 {
-                    Url = series.Images.FirstOrDefault(x => x.CoverType == MediaCoverTypes.Poster).Url
+                    Url = series.Images.FirstOrDefault(x => x.CoverType == MediaCoverTypes.Poster)?.Url
                 };
             }
 
@@ -146,7 +146,7 @@ namespace NzbDrone.Core.Notifications.Discord
             {
                 embed.Image = new DiscordImage
                 {
-                    Url = series.Images.FirstOrDefault(x => x.CoverType == MediaCoverTypes.Fanart).Url
+                    Url = series.Images.FirstOrDefault(x => x.CoverType == MediaCoverTypes.Fanart)?.Url
                 };
             }
 

src/NzbDrone.Core/Notifications/Discord/DiscordSettings.cs

@@ -19,8 +19,8 @@ namespace NzbDrone.Core.Notifications.Discord
         public DiscordSettings()
         {
             //Set Default Fields
-            GrabFields = new List<int> { 0, 1, 2, 3, 5, 6, 7, 8, 9 };
+            GrabFields = new [] { 0, 1, 2, 3, 5, 6, 7, 8, 9 };
-            ImportFields = new List<int> { 0, 1, 2, 3, 4, 6, 7, 8, 9, 10, 11, 12 };
+            ImportFields = new [] { 0, 1, 2, 3, 4, 6, 7, 8, 9, 10, 11, 12 };
         }
 
         private static readonly DiscordSettingsValidator Validator = new DiscordSettingsValidator();