Fixed: Config file settings do not need to be case-sensitive

(cherry picked from commit 2107635b7e7e5392624f2957af7d7b88ba6be283)

Closes #2351

src/NzbDrone.Core/Configuration/ConfigFileProvider.cs

@@ -256,7 +256,7 @@ 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)