salt-master-init.sh: Use stable 2016.11 salt ver

salt-master-init.sh: Use stable 2016.11 salt ver

The <salt-master-init.sh> script default to using stable 2016.3
version of Salt via BOOTSTRAP_SALTSTACK_OPTS.
However, since we manually add the 2016.11 repos beforehand, the
correct version (2016.11) ends up being installed.
This change merely drops one uselss repo from salt master apt sources.

While at it, use HTTPS for repo.saltstack.com DEB repository.

Since we already add the repo to apt sources via <user-data.sh>,
pass "-r" on all architectures, skipping repo (re)addition.

Change-Id: I7fbe0b646b2f2a8e952718a61ff8c180116f8f27
Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>