[COOK-3490] [COOK-3611] Fix Postgresql::ruby on ubuntu/debian and fix config for 9.3

For first issue, see:

https://github.com/opscode-cookbooks/postgresql/commit/0cbdfd466fdd63c379460261f0a6ab930617bcf9#commitcomment-4095320
https://github.com/opscode-cookbooks/postgresql/pull/76

For second issue, see:
https://tickets.opscode.com/browse/COOK-3611