owncloud: Introduce get_webdav_uri() helper
owncloud: Introduce get_webdav_uri() helper

Move a bit more code out of GoaOwncloudProvider::build_object().

https://bugzilla.gnome.org/show_bug.cgi?id=752941

ritzk/gnome-online-accounts,felipeborges/gnome-online-accounts,ritzk/gnome-online-accounts,felipeborges/gnome-online-accounts,ritzk/gnome-online-accounts,felipeborges/gnome-online-accounts