ci/rpmostree: Bump to 2019.1
ci/rpmostree: Bump to 2019.1

Should fix the issue that CI broke due to libsolv not being sync'd.

Closes: #1806
Approved by: jlebon

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