Remove info_hash from failure reason

[alxhotel]

If a client doesn't send the key info_hash (or sends it empty) in the request, then parseWebSocketRequest throws an Error.

Therefore, the key info_hash should not be used in the catch block, otherwise it will throw a TypeError while creating a new Buffer:

buffer.js:188
        throw new TypeError('First argument needs to be a number, ' +
              ^
TypeError: First argument needs to be a number, array or string.
    at new Buffer (buffer.js:188:15)
    at Object.exports.hexToBinary (/tracker2/node_modules/bittorrent-tracker/lib/common.js:15:10)
    at Server._onWebSocketRequest (/tracker2/node_modules/bittorrent-tracker/server.js:316:25)
    at WebSocket.EventEmitter.emit (events.js:98:17)
    at Receiver.ontext (/tracker2/node_modules/bittorrent-tracker/node_modules/ws/lib/WebSocket.js:816:10)
    at /tracker2/node_modules/bittorrent-tracker/node_modules/ws/lib/Receiver.js:477:18
    at /tracker2/node_modules/bittorrent-tracker/node_modules/ws/lib/Receiver.js:361:7
    at /tracker2/node_modules/bittorrent-tracker/node_modules/ws/lib/PerMessageDeflate.js:247:5
    at afterWrite (_stream_writable.js:274:3)
    at onwrite (_stream_writable.js:266:7)

[feross]

Good catch – thank you!

[feross]

Released as 7.3.1.