try to use ssh compression only during sftp
try to use ssh compression only during sftp

When the global cap variable for compression was true:

  ssh_options[:compression] = true

cap tasks were rep[orting this error at the end:

  zlib(finalizer): the stream was freed prematurely.

concord-consortium/rigse,concord-consortium/rigse,concord-consortium/rigse,concord-consortium/rigse,concord-consortium/rigse,concord-consortium/rigse