FIX: try to reduce page fault while idling

jira: [none]
Change-Id: I563cbf4a8ba8a4ae1e5b1b1f735753d3aef23e16
(cherry picked from commit ed1e9678c351dc037f2e3cc7ea0e19d46731699c)

src/slic3r/GUI/TabButton.hpp

@@ -45,6 +45,7 @@ public:
     void Rescale();
 
     void ShowNewTag(bool tag = false) {show_new_tag = tag; Refresh();};
+    bool GetShowNewTag() const { return show_new_tag; };
 
 private:
     void paintEvent(wxPaintEvent& evt);