Finally remove utils.Cfg (#8113)

* finally remove utils.Cfg

* fix compile error

* another test compilation fix

app/user_test.go

@@ -88,10 +88,6 @@ func TestCreateOAuthUser(t *testing.T) {
 
 	th.App.PermanentDeleteUser(user)
 
-	userCreation := th.App.Config().TeamSettings.EnableUserCreation
-	defer th.App.UpdateConfig(func(cfg *model.Config) {
-		cfg.TeamSettings.EnableUserCreation = userCreation
-	})
 	th.App.Config().TeamSettings.EnableUserCreation = false
 
 	_, err = th.App.CreateOAuthUser(model.USER_AUTH_SERVICE_GITLAB, strings.NewReader(json), th.BasicTeam.Id)