ensure that the random number generator(s) are always seeded with a different...

ensure that the random number generator(s) are always seeded with a different value during Asterisk startup
don't reinitialize random number generators in other modules
(bug #4017)


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@5459 65c4cc65-6c06-0410-ace0-fbb531ad65f3