Fix astcanary startup problem due to wrong pid value from before daemon call

When Asterisk forks itself into the background via a call to daemon, it must
re-set the pid value of the new process. Otherwise, astcanary gets the pid
value of the process before the fork, which prevents it from running. Asterisk
eventually starts lowering its priority, as it can no longer communicate
with the proverbial canary in the coal mine.

This patch ensures that the correct process identifier is used by astcanary.

(closes issue ASTERISK-20947)
Reported by: Jakob Hirsch
Tested by: mjordan
patches:
  asterisk-10.12.0.astcanary_ppid.diff uploaded by Jakob Hirsch (license 6113)



git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/1.8@379509 f38db490-d61c-443f-a65b-d21fe96a405b