wxDataViewCustomRenderer::RenderText() taking attributes must use correct
colour for the selected items if no attribute is specified as it can be (and
is) called directly and not only via the compatibility overload.
This fixes the display of the selected items in the dataview sample broken by
recent changes.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@62417 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775