test_cancel_bye.c: added test case 6.4.3 where BYE fails.
test_cancel_bye.c: added test case 6.4.3 where BYE fails.

darcs-hash:20070412143718-65a35-9ecabdc32a50bdbbf87a3caf5594c6770edc0010.gz

unispeech/sofia-sip,BelledonneCommunications/sofia-sip,BelledonneCommunications/sofia-sip,erdincay/sofia-sip,jart/sofia-sip,unispeech/sofia-sip,unispeech/sofia-sip,jart/sofia-sip,unispeech/sofia-sip,erdincay/sofia-sip,BelledonneCommunications/sofia-sip,xhook/sofia-sip,erdincay/sofia-sip,BelledonneCommunications/sofia-sip,xhook/sofia-sip,xhook/sofia-sip,xhook/sofia-sip,erdincay/sofia-sip,xhook/sofia-sip,jart/sofia-sip