Fixed: Support the old broken functionality in `GetValueEnum`

(cherry picked from commit 2c4e1be12ad5e3b8362f83b8185c143f8e66062b)

Fixes #1602

src/NzbDrone.Core/Configuration/ConfigFileProvider.cs

@@ -259,7 +259,7 @@ namespace NzbDrone.Core.Configuration
 
         public T GetValueEnum<T>(string key, T defaultValue, bool persist = true)
         {
-            return (T)Enum.Parse(typeof(T), GetValue(key, defaultValue, persist));
+            return (T)Enum.Parse(typeof(T), GetValue(key, defaultValue, persist), true);
         }
 
         public string GetValue(string key, object defaultValue, bool persist = true)