trusted.gpg.d: keep in the same location
trusted.gpg.d: keep in the same location

With the package rename from ostree to libostree, the trusted.gpg.d/ dir
changed install location from /usr/share/ostree to /usr/share/libostree.
Let's keep the same dir to remain compatible with existing installations
that may already have keys there.

Closes: #668
Approved by: cgwalters

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