VideoConfig: Eliminate NetPlay related members.

Source/Core/DolphinQt/NetPlay/NetPlayDialog.cpp

@@ -805,7 +805,8 @@ void NetPlayDialog::DisplayMessage(const QString& msg, const std::string& color,
 
   QColor c(color.empty() ? QStringLiteral("white") : QString::fromStdString(color));
 
-  if (g_ActiveConfig.bShowNetPlayMessages && Core::IsRunning(Core::System::GetInstance()))
+  if (Config::Get(Config::GFX_SHOW_NETPLAY_MESSAGES) &&
+      Core::IsRunning(Core::System::GetInstance()))
   {
     g_netplay_chat_ui->AppendChat(msg.toStdString(),
                                   {static_cast<float>(c.redF()), static_cast<float>(c.greenF()),