Ceph should never be deployed with an even number of monitors.

Signed-off-by: JuanJose 'JJ' Galvez <jj.galvez@inktank.com>
(cherry picked from commit 49c06c49858eff49534143a033ff0002bcfd6595)
Merge pull request #37 from vuntz/release/stoney/master

Ceph should never be deployed with an even number of monitors.