Summary:
All ssh stderr are prefixed by "remote:", which could be confusing because the
message can also be some errors from the local ssh program. Treat "ssh:" as a
special case and do not prefix it with "remote:".
Reviewed By: markbt
Differential Revision: D10437082
fbshipit-source-id: 37935bd7276969ef17fa5028b02d01e3c9d0bf30
