fix compile against OSRM v0.4.x
fix compile against OSRM v0.4.x

KnockSoftware/node-osrm,oxidase/node-osrm,oxidase/node-osrm,Project-OSRM/node-osrm,Project-OSRM/node-osrm,Project-OSRM/node-osrm,KnockSoftware/node-osrm,KnockSoftware/node-osrm,oxidase/node-osrm,KnockSoftware/node-osrm