Prevent GC saving the perspectives twice (#4636)

The saveState() call results in the loaded perspectives being saved twice when GC exits, once in saveState() and again when the AbstractView's destructor is called.

src/Gui/AthleteTab.cpp

@@ -123,11 +123,6 @@ AthleteTab::~AthleteTab()
 void
 AthleteTab::close()
 {
-    analysisView->saveState();
-    homeView->saveState();
-    trainView->saveState();
-    diaryView->saveState();
-
     analysisView->close();
     homeView->close();
     trainView->close();