Don't fail when G_DEBUG=fatal-warnings is set by default.
Don't fail when G_DEBUG=fatal-warnings is set by default.

* src/client/components/client-web-view.vala
  (ClientWebView::load_user_stylesheet): Don't warn when we can't load
  the user CSS file, since that's likely to be the case.

tshikaboom/geary,tshikaboom/geary,tshikaboom/geary