sshpeer: only print out 'running ssh' messages in debug mode (BC)
Previously, if another command was run with --verbose, and for whatever reason
that invoked sshpeer, we'd get a 'running ssh' message from sshpeer. This extra
line would interfere with that command's output and cause dumb parsers to
break.
For example, hg annotate can be run with --verbose to get full usernames. This,
combined with the third-party remotefilelog extension which can cause ssh
connections to be created, leads to an extra 'running ssh' line that breaks
most parsers.
This patch is (BC) because hg pull --verbose will no longer print out exactly
what ssh command it is running.
No tests are affected by this change.