Fix "Nagios ssh check is automatically added by the ssh module and cantains a wrong hostname on single node setup (Bug #5998)"

before, the ssh module added this check, resulting in a wrong
hostname and the port was always '22'.

manage_nagios parameter is boolean, so we use false instead of 'no'

manually add check_ssh to nagios (#5998)
Merge remote-tracking branch 'varac/5998_fix_nagios_nodename' into 0.5.3