can't deploy to ubuntu 16.04 xenial

Seems that the repo added by the charm is incorrect

related Log:

unit-ceph-mon-10: 15:18:10 DEBUG unit.ceph-mon/10.install W: The repository 'http://ceph.com/debian-luminous xenial Release' is not signed.
unit-ceph-mon-10: 15:18:10 DEBUG unit.ceph-mon/10.install E: Failed to fetch http://ceph.com/debian-luminous/dists/xenial/xenial/binary-amd64/Packages 404 Not Found
unit-ceph-mon-10: 15:18:10 DEBUG unit.ceph-mon/10.install E: Some index files failed to download. They have been ignored, or old ones used instead.
unit-ceph-mon-10: 15:18:10 DEBUG unit.ceph-mon/10.install Traceback (most recent call last):
unit-ceph-mon-10: 15:18:10 DEBUG unit.ceph-mon/10.install File "/var/lib/juju/agents/unit-ceph-mon-10/charm/hooks/install.real", line 725, in <module>
unit-ceph-mon-10: 15:18:10 DEBUG unit.ceph-mon/10.install hooks.execute(sys.argv)
unit-ceph-mon-10: 15:18:10 DEBUG unit.ceph-mon/10.install File "/var/lib/juju/agents/unit-ceph-mon-10/charm/hooks/charmhelpers/core/hookenv.py", line 798, in execute
unit-ceph-mon-10: 15:18:10 DEBUG unit.ceph-mon/10.install self._hooks[hook_name]()
unit-ceph-mon-10: 15:18:10 DEBUG unit.ceph-mon/10.install File "/var/lib/juju/agents/unit-ceph-mon-10/charm/hooks/charmhelpers/contrib/hardening/harden.py", line 79, in _harden_inner2
unit-ceph-mon-10: 15:18:10 DEBUG unit.ceph-mon/10.install return f(*args, **kwargs)
unit-ceph-mon-10: 15:18:10 DEBUG unit.ceph-mon/10.install File "/var/lib/juju/agents/unit-ceph-mon-10/charm/hooks/install.real", line 121, in install
unit-ceph-mon-10: 15:18:10 DEBUG unit.ceph-mon/10.install apt_update(fatal=True)
unit-ceph-mon-10: 15:18:10 DEBUG unit.ceph-mon/10.install File "/var/lib/juju/agents/unit-ceph-mon-10/charm/hooks/charmhelpers/fetch/ubuntu.py", line 228, in apt_update
unit-ceph-mon-10: 15:18:10 DEBUG unit.ceph-mon/10.install _run_apt_command(cmd, fatal)
unit-ceph-mon-10: 15:18:10 DEBUG unit.ceph-mon/10.install File "/var/lib/juju/agents/unit-ceph-mon-10/charm/hooks/charmhelpers/fetch/ubuntu.py", line 559, in _run_apt_command
unit-ceph-mon-10: 15:18:10 DEBUG unit.ceph-mon/10.install retry_message="Couldn't acquire DPKG lock")
unit-ceph-mon-10: 15:18:10 DEBUG unit.ceph-mon/10.install File "/var/lib/juju/agents/unit-ceph-mon-10/charm/hooks/charmhelpers/fetch/ubuntu.py", line 535, in _run_with_retries
unit-ceph-mon-10: 15:18:10 DEBUG unit.ceph-mon/10.install result = subprocess.check_call(cmd, **kwargs)
unit-ceph-mon-10: 15:18:10 DEBUG unit.ceph-mon/10.install File "/usr/lib/python3.5/subprocess.py", line 581, in check_call
unit-ceph-mon-10: 15:18:10 DEBUG unit.ceph-mon/10.install raise CalledProcessError(retcode, cmd)
unit-ceph-mon-10: 15:18:10 DEBUG unit.ceph-mon/10.install subprocess.CalledProcessError: Command '['apt-get', 'update']' returned non-zero exit status 100
unit-ceph-mon-10: 15:18:10 ERROR juju.worker.uniter.operation hook "install" failed: exit status 1
unit-ceph-mon-10: 15:18:10 DEBUG juju.worker.uniter.operation lock released
unit-ceph-mon-10: 15:18:10 INFO juju.worker.uniter awaiting error resolution for "install" hook
unit-ceph-mon-10: 15:18:10 DEBUG juju.worker.uniter [AGENT-STATUS] error: hook failed: "install"

Solved by:
just going to the node and adjust the repo to:
'deb https://download.ceph.com/debian-luminous/ xenial main'
instead of
'deb http://ceph.com/debian-luminous xenial Release'