plumbing: ssh, Fix flaky test TestAdvertisedReferencesNotExists. Fixes #969
plumbing: ssh, Fix flaky test TestAdvertisedReferencesNotExists. Fixes #969

Signed-off-by: Colton McCurdy <e350c072cd003e0ce827ffb70cb46534f876b320@gmail.com>

go-git/go-git,go-git/go-git,src-d/go-git,mcuadros/go-git,mcuadros/go-git,src-d/go-git