Fix another node 0.10.x compile error.
Fix another node 0.10.x compile error.

michaelkyriacou/node-geoip2,DeadAlready/node-geoip2,DeadAlready/node-geoip2,DeadAlready/node-geoip2,davidtsai/node-geoip2,davidtsai/node-geoip2,michaelkyriacou/node-geoip2,davidtsai/node-geoip2,michaelkyriacou/node-geoip2