Fixed compilation errors due to refactor

Author: openbullet

OpenBullet2.Core/Helpers/Mapper.cs

@@ -14,7 +14,7 @@ public static class Mapper
         Country = proxy.Country,
         Host = proxy.Host,
         Port = proxy.Port,
-        LastChecked = proxy.LastChecked,
+        LastChecked = proxy.LastChecked.Value,
         Username = proxy.Username,
         Password = proxy.Password,
         Ping = proxy.Ping,

OpenBullet2.Core/Models/Proxies/DatabaseProxyCheckOutput.cs

@@ -30,7 +30,7 @@ public async Task StoreAsync(Proxy proxy)
         {
             var entity = await _proxyRepo.GetAsync(proxy.Id);
             entity.Country = proxy.Country;
-            entity.LastChecked = proxy.LastChecked;
+            entity.LastChecked = proxy.LastChecked.Value;
             entity.Ping = proxy.Ping;
             entity.Status = proxy.WorkingStatus;