pull: Explicitly use thread-default main context
pull: Explicitly use thread-default main context

As preparation for pushing our own temporary context.

GNOME/ostree,sujitfulse/ostree,sujitfulse/ostree,GNOME/ostree,gatispaeglis/ostree,sujitfulse/ostree,GNOME/ostree,resin-io/ostree,leandrosansilva/ostree,leandrosansilva/ostree,GNOME/ostree,leandrosansilva/ostree,sujitfulse/ostree,gatispaeglis/ostree,resin-io/ostree,leandrosansilva/ostree,gatispaeglis/ostree,sujitfulse/ostree,leandrosansilva/ostree,resin-io/ostree,resin-io/ostree,resin-io/ostree,GNOME/ostree,gatispaeglis/ostree,gatispaeglis/ostree,gatispaeglis/ostree