Uncaught exception on empty POST request

[WillyKaze]

firenodejs crash when an empty POST request is received:

HTTP : POST /firestep <= {}
TTY : WRITE(4) {}\n
TTY : READ(4) {"s":-118} \n
HTTP : firenodejs UNCAUGHT EXCEPTION:TypeError: Cannot read property 'id' of undefined
/home/fpd/repos/firenodejs/js/server.js:588
 throw error;
 ^

TypeError: Cannot read property 'id' of undefined
 at FireStepPlanner.onResponse (/home/fpd/repos/firenodejs/js/firestep/planner.js:365:26)
 at Object.response (/home/fpd/repos/firenodejs/js/firestep/planner.js:27:18)
 at FireStepDriver.onSerialData (/home/fpd/repos/firenodejs/js/firestep/driver.js:244:27)
 at Socket.<anonymous> (/home/fpd/repos/firenodejs/js/firestep/driver.js:83:26)
 at emitOne (events.js:90:13)
 at Socket.emit (events.js:182:7)
 at readableAddChunk (_stream_readable.js:147:16)
 at Socket.Readable.push (_stream_readable.js:111:10)
 at Pipe.onread (net.js:523:20)