dav: Don't use deprecated libsoup methods
dav: Don't use deprecated libsoup methods

https://bugzilla.gnome.org/show_bug.cgi?id=682990

philipl/gvfs,xkahn/gvfs-cmis,gicmo/gvfs,gicmo/gvfs,philipl/gvfs,xkahn/gvfs-cmis,xkahn/gvfs-cmis,gicmo/gvfs,halfline/gvfs,halfline/gvfs,gicmo/gvfs,philipl/gvfs,xkahn/gvfs-cmis,halfline/gvfs