Recent breaking changes to websockets/ws break websockify.js

[samfrances]

See: websockets/ws#1099

The client.upgradeReq property has been removed in the ws module, leading websockify.js to crash at https://github.com/novnc/websockify/blob/master/other/js/websockify.js#L31

Error message:

WebSocket settings:
    - proxying from :6080 to localhost:5900
    - Running in unencrypted HTTP (ws://) mode
/home/sam/websockify_node/websockify.js:31
    console.log(client.upgradeReq.url);
                                 ^

TypeError: Cannot read property 'url' of undefined
    at WebSocketServer.new_client (/home/sam/websockify_node/w
ebsockify.js:31:34)
    at emitTwo (events.js:106:13)
    at WebSocketServer.emit (events.js:191:7)
    at handleUpgrade (/home/sam/websockify_node/node_modules/w
s/lib/WebSocketServer.js:88:16)
    at WebSocketServer.completeUpgrade (/home/sam/websockify_n
ode/node_modules/ws/lib/WebSocketServer.js:270:5)
    at WebSocketServer.handleUpgrade (/home/sam/websockify_nod
e/node_modules/ws/lib/WebSocketServer.js:197:10)
    at Server.WebSocketServer._ultron.on (/home/sam/websockify
_node/node_modules/ws/lib/WebSocketServer.js:87:14)
    at emitThree (events.js:116:13)
    at Server.emit (events.js:194:7)
    at onParserExecuteCommon (_http_server.js:409:14)

[samfrances]

I have posted a pull request which ought to fix this bug. novnc/websockify#281