Fix libraries order in screenshotgen bakefile.

Fix libraries order in screenshotgen bakefile.

The richtext library must come before the adv one as it depends on the classes
in the latter and with the old libraries order linking failed in static build.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@67033 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775