Document connectedline parameter for chan_iax2

The connectedline parameter for a chan_iax2 peer was undocumented. This patch
documents the options in the sample configuration file.

(closes issue ASTERISK-21953)
Reported by: Birger "WIMPy" Harzenetter
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Merged revisions 394886 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 394890 from http://svn.asterisk.org/svn/asterisk/branches/11


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@394894 65c4cc65-6c06-0410-ace0-fbb531ad65f3

configs/iax.conf.sample

@@ -608,6 +608,15 @@ description=Demo System At Digium    ; Description of this peer, as listed by
 ; IPs can also optionally be given but are not required.  Caller*ID can be
 ; suggested to the other side as well if it is for example a phone instead of
 ; another PBX.
+;connectedline=yes ; Set how connected line information is handled for this
+;                  ; peer. If set to "yes", both sending and receiving
+;                  ; connected line information will be enabled. If set to
+;                  ; "send", this peer will send connected line information
+;                  ; but will not process connected line updates. If set to
+;                  ; "receive", connected line updates will be processed
+;                  ; but not sent. If set to "no", connected line updates
+;                  ; will be disabled. Default is "no".
+
 
 ;[dynamichost]
 ;host=dynamic