Update the sip-friends.sql file to use the non-deprecated 'defaultname'...

Update the sip-friends.sql file to use the non-deprecated 'defaultname' instead of 'username' and remove an extra comma that would cause the script to fail as-is

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@167373 65c4cc65-6c06-0410-ace0-fbb531ad65f3