bugfix: serialize the message before copying and storing it.
bugfix: serialize the message before copying and storing it.

BelledonneCommunications/flexisip,BelledonneCommunications/flexisip,biddyweb/flexisip,gale320/flexisip,BelledonneCommunications/flexisip,gale320/flexisip,BelledonneCommunications/flexisip,biddyweb/flexisip,biddyweb/flexisip,biddyweb/flexisip,gale320/flexisip,gale320/flexisip