sipe-sign: fix parsing of P-Asserted-Identity header
- add support for previously unrecognized header format
P-Asserted-Identity: "Lunch, Lucas" <sip:llucas@cisco.com>,<tel:+
420123456;ext=88463>
where tel: URI was not parsed out and later missing in message signature
check, causing validation to fail.
- added support for header in format
P-Asserted-Identity: tel:+
14085264000
that was documented as valid, but not recognized by previous implementation
(cherry picked from commit
17f2653e3395fdd4067ff42f130a6a16de2f8e95)