Don't re-create wxChoice with proportion of 1

When re-creating a wxChoice in the widgets sample it expands vertically.
Same fix as dd740d8 (ticket #9594) but for the Choice page instead of
Combobox page.

samples/widgets/choice.cpp

@@ -314,7 +314,7 @@ void ChoiceWidgetsPage::CreateChoice()
                             flags);
 
     m_choice->Set(items);
-    m_sizerChoice->Add(m_choice, 1, wxGROW | wxALL, 5);
+    m_sizerChoice->Add(m_choice, 0, wxGROW | wxALL, 5);
     m_sizerChoice->Layout();
 }