pull: Ensure queued filemeta requests don't starve everything else
pull: Ensure queued filemeta requests don't starve everything else

We need this hack for "archive mode" repositories; otherwise,
what ends up happening is that we get 10000+ requests pending
for .filemeta files, which we can't process until we also get
the .filecontent.

Note this hack is unneccessary when fetching from archive-z
repositories.

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