Don't lowercase UrlBase in ConfigFileProvider

UrlBase should honour the case it is given.

(cherry picked from commit e1de523c89f7649e64f520b090bbdb2f56cc4b85)

src/NzbDrone.Core/Configuration/ConfigFileProvider.cs

@@ -221,7 +221,7 @@ namespace NzbDrone.Core.Configuration
                     return urlBase;
                 }
 
-                return "/" + urlBase.Trim('/').ToLower();
+                return "/" + urlBase;
             }
         }