BUG #3809: SSL "unsafe" private key permissions bug

The following bug has been logged online:

Bug reference:      3809
Logged by:          Simon Arlott
Email address:      postgresql.simon@arlott.org
PostgreSQL version: 8.2.4
Operating system:   Linux 2.6.23
Description:        SSL "unsafe" private key permissions bug
Details:

FATAL:  unsafe permissions on private key file "server.key"
DETAIL:  File must be owned by the database user and must have no
permissions for "group" or "other".

It should be possible to disable this check in the configuration, so those
of us capable of deciding what's unsafe can do so.