Blind fixes for warnings in wxTinderbox.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@37168 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/univ/combobox.h

@@ -66,6 +66,7 @@ class WXDLLEXPORT wxComboPopup
 {
 public:
     wxComboPopup(wxComboControl *combo) { m_combo = combo; }
+    virtual ~wxComboPopup() {}
 
     // we must have an associated control which is subclassed by the combobox
     virtual wxControl *GetControl() = 0;