collection_backend_child_added: Inherit OAuth 2.0 support.
collection_backend_child_added: Inherit OAuth 2.0 support.

Collection children will inherit the collection source's EOAuth2Support
object if set.  That way OAuth 2.0 availability is consistent across the
entire collection, even if it's not USED by all sources in the collection.

matzipan/evolution-data-server,matzipan/evolution-data-server,tintou/evolution-data-server,Distrotech/evolution-data-server,tintou/evolution-data-server,tintou/evolution-data-server,matzipan/evolution-data-server,Distrotech/evolution-data-server,Distrotech/evolution-data-server,matzipan/evolution-data-server,Distrotech/evolution-data-server,Distrotech/evolution-data-server,tintou/evolution-data-server,matzipan/evolution-data-server