Fix Login GUI not respecting other GUIs opened on startup

Previously the Login GUI would simply replace the currently active GUI.
Now the currently active GUI is stored and then re-opened after login.

src/main/java/com/replaymod/online/ReplayModOnline.java

@@ -82,7 +82,7 @@ public class ReplayModOnline {
         // Initial login prompt
         if (!core.getSettingsRegistry().get(Setting.SKIP_LOGIN_PROMPT)) {
             if (!isLoggedIn()) {
-                new GuiLoginPrompt(apiClient, null, null, false).display();
+                core.runLater(() -> new GuiLoginPrompt(apiClient, GuiScreen.wrap(getMinecraft().currentScreen), null, false).display());
             }
         }
     }