Revert "Swap to dapper and system.text.json for database backend"

This reverts commit d2065bfa1b.

src/NzbDrone.Core/Configuration/ConfigRepository.cs

@@ -18,9 +18,10 @@ namespace NzbDrone.Core.Configuration
         {
         }
 
+
         public Config Get(string key)
         {
-            return Query(c => c.Key == key).SingleOrDefault();
+            return Query.Where(c => c.Key == key).SingleOrDefault();
         }
 
         public Config Upsert(string key, string value)