ENH: dual extruder nozzle setting on sidebar

Change-Id: I7bc4209b311360c3357e3974f0e66a51daa78232
(cherry picked from commit 507c6a9b2cc4f854ef78acd07bc452ffb21b6bdb)

src/slic3r/GUI/Plater.hpp

@@ -204,7 +204,6 @@ private:
     std::unique_ptr<priv> p;
 
     wxBoxSizer* m_scrolled_sizer = nullptr;
-    ComboBox* m_bed_type_list = nullptr;
     ScalableButton* connection_btn = nullptr;
     ScalableButton* ams_btn = nullptr;
 };