Don't allow border-radius in headerbars when using server-side decorations
Don't allow border-radius in headerbars when using server-side decorations

The Ambiance theme isn't smart enough to give headerbars square corners
when they aren't being used as title bars.  In this case, they're always
inside vertical Gtk.Boxes, so we target a CSS rule at that.

https://bugzilla.gnome.org/show_bug.cgi?id=746172

AtticHacker/geary,martinra/geary,aatishnn/geary,robol/geary,tshikaboom/geary,emersion/geary,emersion/geary,martinra/geary,mjog/geary,mjog/geary,mjog/geary,aatishnn/geary,AtticHacker/geary,AtticHacker/geary,martinra/geary,emersion/geary,tshikaboom/geary,githubnemo/geary,jimbonator/geary,glebihan/geary,glebihan/geary,jimbonator/geary,githubnemo/geary,robol/geary,githubnemo/geary,tshikaboom/geary,glebihan/geary,aatishnn/geary,robol/geary,jimbonator/geary