[core] HttpRequest: adapted to changes in Buffer API
[core] HttpRequest: adapted to changes in Buffer API

christianparpart/x0,xzero/x0,christianparpart/x0,christianparpart/x0,christianparpart/x0,xzero/x0,christianparpart/x0,xzero/x0,christianparpart/x0,xzero/x0,xzero/x0,xzero/x0,christianparpart/x0