Code review comment for lp:~jjo/charm-helpers/fix-check_haproxy_sh-lp1521279

This patch looks good to me, I tested it using trusty-icehouse and trusty-liberty, there are no visible regressions and it fixes liberty.

[0] trusty-icehouse:
root@juju-freyes-machine-4:~# /usr/local/lib/nagios/plugins/check_haproxy.sh
OK: All haproxy instances (6) looking good
root@juju-freyes-machine-4:~# service haproxy stop
 * Stopping haproxy haproxy
   ...done.
root@juju-freyes-machine-4:~# /usr/local/lib/nagios/plugins/check_haproxy.sh
CRITICAL: keystone-1 keystone-0 keystone-2 keystone-1 keystone-0 keystone-2
root@juju-freyes-machine-4:~# service haproxy start
 * Starting haproxy haproxy
   ...done.
root@juju-freyes-machine-4:~# /usr/local/lib/nagios/plugins/check_haproxy.sh
OK: All haproxy instances (6) looking good

[1] trusty-liberty:
root@juju-freyes-machine-4:~# /usr/local/lib/nagios/plugins/check_haproxy.sh
CRITICAL: keystone-1 keystone-0 keystone-2 keystone-1 keystone-0 keystone-2
root@juju-freyes-machine-4:~# service haproxy status
haproxy is running.
root@juju-freyes-machine-4:~# dpkg -l haproxy
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-===============================================-============================-============================-===================================================================================================
ii haproxy 1.5.14-1ubuntu0.15.10.1~clou amd64 fast and reliable load balancing reverse proxy
root@juju-freyes-machine-4:~# /usr/local/lib/nagios/plugins/check_haproxy.sh #<-patched
OK: All haproxy instances (6) looking good