app-admin/rsyslog: Bumped to v8.4.2

- bugfix: the fix for CVE-2014-3634 did not handle all cases
  This is corrected now.
  see also: CVE-2014-3683
- fixed a build problem on some platforms
  Thanks to Olaf for the patch
- behaviour change: "msg" of messages with invalid PRI set to "rawmsg"
  When the PRI is invalid, the rest of the header cannot be valid. So
  we move all of it to MSG and do not try to parse it out. Note that
  this is not directly related to the security issue but rather done
  because it makes most sense.

Gentoo:

- Respect CFlag patch added (remove "-g" flag")