Merged revisions 162738 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.4

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  r162738 | file | 2008-12-10 13:50:43 -0400 (Wed, 10 Dec 2008) | 6 lines
  
  When a SIP peer unregisters set the expiry time back to 0 so that the 200 OK contains an expires of 0.
  (closes issue #13599)
  Reported by: hjourdain
  Patches:
        chan_sip.c.diff uploaded by hjourdain (license 583)
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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@162739 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -11118,6 +11118,7 @@ static enum parse_register_result parse_register_contact(struct sip_pvt *pvt, st
 		ast_string_field_set(peer, useragent, "");
 		peer->sipoptions = 0;
 		peer->lastms = 0;
+		pvt->expiry = 0;
 
 		ast_verb(3, "Unregistered SIP '%s'\n", peer->name);