conversationmodel: connect callback earlier for SIP account
conversationmodel: connect callback earlier for SIP account

Because the action is immediate for SIP accounts, the callback
should be created earlier to avoid to miss the signal.

Change-Id: Ia189c8c499093f3993020a9ed69d4e7d386a167e

savoirfairelinux/ring-lrc,savoirfairelinux/ring-lrc,savoirfairelinux/ring-lrc,savoirfairelinux/ring-lrc,savoirfairelinux/ring-lrc