sanitize_tdata was assuming all URIs were SIP URIs so when a non
SIP uri was in the From, To or Contact headers, the unconditional
cast of a non-pjsip_sip_uri structure to pjsip_sip_uri caused
a segfault when trying to access uri->other_param.

* Added PJSIP_URI_SCHEME_IS_SIP(uri) || PJSIP_URI_SCHEME_IS_SIPS(uri)
  checks before attempting to cast or use the returned uri.

ASTERISK-27152
Reported-by: Ross Beer

Change-Id: Id380df790e6622c8058a96035f8b8f4aa0b8551f