Initialize an uninitialized variable.

(closes issue #18640)
Reported by: jcovert
Patches:
      chan_sip.c.patch uploaded by jcovert (license 551)


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@302414 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -12978,7 +12978,7 @@ static enum parse_register_result parse_register_contact(struct sip_pvt *pvt, st
 	char *firstcuri = NULL;
 	int start = 0;
 	int wildcard_found = 0;
-	int single_binding_found;
+	int single_binding_found = 0;
 
 	ast_copy_string(contact, __get_header(req, "Contact", &start), sizeof(contact));