* nta.c: use consistently uint32_t when handling millisecond timers inside nta
  
  The timer handling failed miserably on 64-bit platforms each time uint32_t
  counter for milliseconds wrapped around.



git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@8287 d0543943-73ff-0310-b7d9-9358b9ac24b2