The peer is the last component of the fabric codebase which still has a
dependency on the older mutable channelconfig.  In order to remove the
mutable code pieces, this dependency must be removed.  This CR does just
that.

Change-Id: I1d9f55fccecca6d58006795dda89fd2082c03375
Signed-off-by: Jason Yellick <jyellick@us.ibm.com>