nta.c: when completing a request message, use existing CSeq if leg has no Call-ID.
nta.c: when completing a request message, use existing CSeq if leg has no Call-ID.

darcs-hash:20070223121343-55b16-9c5b45351506978cc3fcb2ac3434cfb85cd93ab6.gz

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