calamari-server.postinst: clean up tabs

Signed-off-by: Dan Mick <dan.mick@inktank.com>
calamari-server.postinst: work around salt-master restart bug

https://github.com/saltstack/salt/issues/12248
stop, killall, start should make us immune until this is fixed upstream

Signed-off-by: Dan Mick <dan.mick@inktank.com>