Sahara-engine uses netcat in the neutron namespace to build a session
when use_namespaces=true, see utils/ssh_remote.py in sahara source code.
Change I8a90d33f0b7b902e059077c3b9fd32ba7b7d7df4 added netcat to the
sahara-engine image for source builds. This change does the same for
binary builds.
Change-Id: I571236d127e34da79367ec4686d7d64430a22fc8
Related-Bug: #1687624
Closes-Bug: #1687602
f8285c336a