Fix a bug when using zaptel timing for playing back files that have a sample rate
other than 8 kHz. The issue here is that format modules give a "whennext" sample
value, which is used to calculate when to set a timer for to retrieve the next
frame. However, the zaptel timer operates on 8 kHz samples, so this must be taken
into account.
(another part of issue #12164, reported by milazzo and jsmith, patch by me)
git-svn-id: http://svn.digium.com/svn/asterisk/trunk@110303 614ede4d-c843-0410-af14-a771ab80d22e