Bug#1141076: `pam_start_confdir()` does not use `confdir` for include and substack directives.

[Ted Lyngmo]

The `conf=` bug isn't Debian specific so I've filed this:

https://github.com/libpwquality/libpwquality/issues/118

The Debian bug 1141076 can be closed as solved in 1.7.0-6.

Br,
Ted