Fix a bug that makes Vk to be always displayed when trying to show any service's config.

Call stack: SettingsDialog::showEvent -> VkSettingsPage::Load -> VkService::ReloadSettings -> VkService::Logout -> VkService::UpdateRoot -> VkService::ShowConfig
Would probably be better to not call service in VkSettingsPage::Load and read QSettings only, but I don't think it's good either to call ShowConfig when user is being logged-out.

src/internet/vkservice.cpp

@@ -546,8 +546,6 @@ void VkService::Logout() {
     client_->disconnectFromHost();
     connection_->clear();
   }
-
-  UpdateRoot();
 }
 
 bool VkService::HasAccount() const { return connection_->hasAccount(); }