Let GitLab runners use GitLab repository directly.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20201022123302.2884788-1-philmd@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>