Added missing includes

src/slic3r/GUI/GUI_Utils.hpp

@@ -16,6 +16,7 @@
 #include <wx/panel.h>
 #include <wx/dcclient.h>
 #include <wx/debug.h>
+#include <wx/settings.h>
 
 class wxCheckBox;
 class wxTopLevelWindow;

src/slic3r/GUI/MainFrame.hpp

@@ -4,6 +4,7 @@
 #include "libslic3r/PrintConfig.hpp"
 
 #include <wx/frame.h>
+#include <wx/settings.h>
 #include <wx/string.h>
 
 #include <string>