Suppress edit of items of UnsavedChangesDialog, fixed update of the information line

+ added white version for icons "exit" and "switch_presets"

src/slic3r/GUI/UnsavedChangesDialog.hpp

@@ -210,9 +210,6 @@ class UnsavedChangesDialog : public DPIDialog
     // selected action after Dialog closing
     Action m_exit_action {Action::Undef};
 
-    // Action during mouse motion
-    Action m_motion_action {Action::Undef};
-
     struct ItemData
     {
         std::string     opt_key;