[check_postgres] Allow dots and dashes in database names in function check_backends

[Davide Abrigo]

Hello,

using version 2.9.1 of check_postgres plugin, i modified line 2263 from:

      SLURP: while ($db->{slurp} =~ /(\d+) \| (\d+)\s+\|\s+(\w+)\s*/gsm) {

to:

      SLURP: while ($db->{slurp} =~ /(\d+) \| (\d+)\s+\|\s+([\w\-\.]+)\s*/gsm) {

since i have database names with dots and dashes in between (like
'www.my-test-db.com')

Bye,
Davide