lib/pull: Only look for cookie files for non-local remotes
lib/pull: Only look for cookie files for non-local remotes

Just noticed this while reading an strace.

Closes: https://github.com/ostreedev/ostree/issues/1139

Closes: #1145
Approved by: jlebon

GNOME/ostree,GNOME/ostree,GNOME/ostree,GNOME/ostree,GNOME/ostree