[packagers] Nagios POSTIN script - usermod -G problem

[Kamil Christ]

>From nagios POSTIN script:

[...]
                /usr/sbin/usermod -G nagios,nagiocmd apache &>/dev/null

usermod -G SETS apache's groups to nagios and nagiocmd removing apache from
other groups and potentially breaking other applications

It should be:
                /usr/bin/gpasswd -a apache nagios &>/dev/null
                /usr/bin/gpasswd -a apache nagiocmd &>/dev/null

Kind regards
Kamil Christ

PS: Thanks for great job!