Remove unnecessary SetInitialSize() from wxGTK wxComboBox::Create().

SetInitialSize() is already done by PostCreation() called just above, no need
to call it twice.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72716 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/combobox.cpp

@@ -187,8 +187,6 @@ bool wxComboBox::Create( wxWindow *parent, wxWindowID id, const wxString& value,
                           G_CALLBACK (gtkcombobox_popupshown_callback), this);
     }
 
-    SetInitialSize(size); // need this too because this is a wxControlWithItems
-
     return true;
 }