Add availability perfdata to "connection"

[jbeaujour]

Hello,
It would be appreciated to add availability perfdata to "connection" action like this
command : check_postgres.pl --action "connection" --host HOST --port 5432 --dbuser USER --showperf=1 --timeout 5 --showtime=0
OK result : POSTGRES_CONNECTION OK: DB "postgres" (host:HOST) version N.n.n | postgres=1;0;0
CRITICAL result : POSTGRES_CONNECTION CRITICAL: DB "postgres" (host:HOST) version N.n.n | postgres=0;0;0

thank's