Invalidate best size after wxChoice::SetString()

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@46234 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/choice.cpp

@@ -382,6 +382,8 @@ void wxChoice::SetString(unsigned int n, const wxString& str)
 
             gtk_label_set_text( label, wxGTK_CONV( str ) );
 
+            InvalidateBestSize();
+
             return;
         }
         child = child->next;