Make the behavior of using /dev/urandom for random numbers the same as random().

(closes issue #11348)
Reported by: sperreault
Patches:
      ast_random2.diff uploaded by sperreault (license 252)


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@89576 65c4cc65-6c06-0410-ace0-fbb531ad65f3