distro/redhat/rpm: remove with_ipv6, package pimd binary, remove pam stack

* redhat/quagga.spec.in: remove with_ipv6, it should just be the norm now.
  The actual pimd binary wasn't being packaged, fix.
  Remove deprecated pam.stack support.

* redhat/quagga.pam.stack: ancient, nuke.
* Makefile.am: ditto
3 files changed