Attempting to use channel 16 on E1 CAS is disallowed since that channel is
reserved for RBS signaling. Configurations should not be generated that
attempt to use it.
Closes DAHDI-763.
Patch by dmartinez.
git-svn-id: http://svn.astersk.org/svn/dahdi/tools/trunk@9485 17933a7a-c749-41c5-a318-cba88f637d49