configs: Comment out and change IP of iax.conf [demo]

This no longer appears to exist, so no sense in causing confusion.

ASTERISK-27175 #close
Reported by: Tzafrir Cohen

Change-Id: Idde967924c69f6a741dc9a5ab7dacb44d22cf100

configs/samples/iax.conf.sample

@@ -572,12 +572,12 @@ inkeys=freeworlddialup
 ;
 ; Peers may also be specified, with a secret and a remote hostname.
 ;
-[demo]
-type=peer
-username=asterisk
-secret=supersecret
-host=216.207.245.47
-description=Demo System At Digium    ; Description of this peer, as listed by
+;[demo]
+;type=peer
+;username=asterisk
+;secret=supersecret
+;host=192.168.10.10
+;description=My IAX2 Peer            ; Description of this peer, as listed by
                                      ; 'iax2 show peers'
 ;sendani=no
 ;host=asterisk.linux-support.net