remote: use VIR_DRV_OPEN_REMOTE_USER in ssh transport checks

remote: use VIR_DRV_OPEN_REMOTE_USER in ssh transport checks

We currently refuse to connect to remote libvirtd over SSH if we see the
path ends in /session. Earlier on though we checked for /session and set
the VIR_DRV_OPEN_REMOTE_USER flag. There is one subtle distinction
though with the test driver. All test URIs are marked with this flag,
regardless of whether the URI indicates a local or remote connection.
Previously a local connection to the test driver would have used the
unprivileged libvirtd while a remote connection would have tried the
privileged libvirtd. With this we are consistent and use the
unprivileged for both local & remote, if the current user is non-root.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>