lib/repo-pull: fix GPG check while pulling remote

lib/repo-pull: fix GPG check while pulling remote

If GPG support is disabled in a build time we should to check if any of
options "gpg_verify" or "gpg_verify_summary" is set to TRUE instead
of checking if they are passed via options while pulling from remote.

Fixed the failure with assertion of `ostree find-remotes --pull --mirror`
calling (`tests/test-pull-collections.sh`) if libostree has been compiled
without GPG support.

Signed-off-by: Denis Pynkin <denis.pynkin@collabora.com>