fix (nuageinit): SSH keys are not handled in metadata but in userdata
MFC After: 1 day
Approved by: re (cperciva)
(cherry picked from commit 48edad2edf6eb7a539e40dad8e1f87e3fa4973fd)
(cherry picked from commit 5601feb7204b2ebb4c351b534105da8fc22213fd)