remote download: set binary mode before size() cmd
remote download: set binary mode before size() cmd

Commands like DIR automatically set ASCII mode
Some servers (ProFTPd) refuse size() in ASCII mode, so we must restore binary
mode before asking for the size

Change-Id: I803a86acdcb971ea2e2e98a9bc4c0282edd4c56f
Reviewed-on: http://gerrit.aldebaran.lan/37899
Tested-by: gerrit
Reviewed-by: vbarbaresi <371b46c96c99af52f4f920034e4fcb63ece5bdb5@aldebaran-robotics.com>

dmerejkowsky/qibuild,aldebaran/qibuild,dmerejkowsky/qibuild,aldebaran/qibuild,dmerejkowsky/qibuild,aldebaran/qibuild,dmerejkowsky/qibuild,dmerejkowsky/qibuild,aldebaran/qibuild