Fix odd "thank you" sound playing behavior in app_queue.c

Fix odd "thank you" sound playing behavior in app_queue.c

If someone has configured the queue to play an position or holdtime
announcement, then it is odd and potentially unexpected to hear a
"Thank you for your patience" sound when no position or holdtime
was actually announced.

This fixes the announcement so that the "thanks" sound is only played
in the case that a position or holdtime was actually announced.

There is a way that the "thank you" sound can be played without a
position or holdtime, and that is to set announce-frequency to a value
but keep announce-position and announce-holdtime both turned off.

(closes issue #14227)
Reported by: caspy
Patches:
      14227_v3.patch uploaded by putnopvut (license 60)
Tested by: caspy

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@174948 65c4cc65-6c06-0410-ace0-fbb531ad65f3