Made companding law for SS7 calls only determined by SS7 signaling type.

Made companding law for SS7 calls only determined by SS7 signaling type.

For SS7, the companding law for a call was chosen inconsistently depending
upon ss7type (ITU vs ANSI) and the DAHDI companding default (T1 vs E1).
For incoming calls, the companding law was determined by ss7type.  For
outgoing calls, the companding law was determined by the DAHDI default.
With the wrong combination you would get A-law/u-law conflicts.  An
A-law/u-law conflict sounds like bad static on the line.

SS7 ITU  signaling with E1 line: ok
SS7 ITU  signaling with T1 line: noise
SS7 ANSI signaling with E1 line: noise
SS7 ANSI signaling with T1 line: ok

* Fix the companding law used to be determined by the SS7 signaling type
only.

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@373090 65c4cc65-6c06-0410-ace0-fbb531ad65f3