[Crash fix]

Fixed crash that occurs when exiting to the main menu through the pause screen while the game window is minimized or not active in general.

P3D/Screens/MainMenu/PauseScreen.vb

@@ -78,10 +78,12 @@
 
         Screen.TextBox.reDelay = 0.0F
 
-        If Me.menuIndex = 0 Then
+        If Core.GameInstance.IsActive = True Then
-            UpdateMain()
+            If Me.menuIndex = 0 Then
-        Else
+                UpdateMain()
-            UpdateQuit()
+            Else
+                UpdateQuit()
+            End If
         End If
     End Sub