Remove dead Torznab presets

src/NzbDrone.Core/Indexers/Torznab/Torznab.cs

@@ -49,9 +49,7 @@ namespace NzbDrone.Core.Indexers.Torznab
         {
             get
             {
-                yield return GetDefinition("HD4Free.xyz", GetSettings("http://hd4free.xyz"));
                 yield return GetDefinition("AnimeTosho Torrents", GetSettings("https://feed.animetosho.org", apiPath: @"/nabapi", categories: Array.Empty<int>(), animeCategories: new[] { 5070 }));
-                yield return GetDefinition("Nyaa Pantsu", GetSettings("https://nyaa.pantsu.cat", apiPath: @"/feed/torznab", categories: Array.Empty<int>(), animeCategories: new[] { 5070 }));
             }
         }
 

src/NzbDrone.Core/Indexers/Torznab/TorznabSettings.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Linq;
 using System.Text.RegularExpressions;
 using FluentValidation;
@@ -10,10 +11,7 @@ namespace NzbDrone.Core.Indexers.Torznab
 {
     public class TorznabSettingsValidator : AbstractValidator<TorznabSettings>
     {
-        private static readonly string[] ApiKeyWhiteList =
+        private static readonly string[] ApiKeyWhiteList = Array.Empty<string>();
-        {
-            "hd4free.xyz",
-        };
 
         private static bool ShouldHaveApiKey(TorznabSettings settings)
         {