Fix crash occuring when a REGISTER containing a contact URI without scheme is received
Fix crash occuring when a REGISTER containing a contact URI without scheme is received

e.g. `Contact: lime` is parsed as URI without scheme and with 'lime' as hostname

BelledonneCommunications/flexisip,BelledonneCommunications/flexisip,BelledonneCommunications/flexisip,BelledonneCommunications/flexisip