Make trunkfreq take effect when set

Make trunkfreq take effect when set

Previously, setting trunkfreq had no effect on initial load or on reload and
only ever used the default value.  This causes trunkfreq to be used
appropriately on initial load and reload.

(closes issue ASTERISK-19521)
Patch-by: Jaco Kroon
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Merged revisions 361972 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 361981 from http://svn.asterisk.org/svn/asterisk/branches/10

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@361987 65c4cc65-6c06-0410-ace0-fbb531ad65f3