Fixed "Cannot read property 'prototype' of undefined"

[amok]

Related: http-party/node-http-proxy/issues/809

trace:

Registering "grunt-bbb-server" local Npm module tasks.
Reading /DIR/node_modules/grunt-bbb-server/package.json...OK
Parsing /DIR/node_modules/grunt-bbb-server/package.json...OK
Loading "server.js" tasks...ERROR
>> TypeError: Cannot read property 'prototype' of undefined
>>     at Object.exports.inherits (util.js:634:43)
>>     at Object.<anonymous> (/DIR/node_modules/grunt-bbb-server/node_modules/http-proxy/lib/http-proxy/index.js:108:17)
>>     at Module._compile (module.js:460:26)
>>     at Object.Module._extensions..js (module.js:478:10)
>>     at Module.load (module.js:355:32)
>>     at Function.Module._load (module.js:310:12)
>>     at Module.require (module.js:365:17)
>>     at require (module.js:384:17)
>>     at Object.<anonymous> (/DIR/node_modules/grunt-bbb-server/node_modules/http-proxy/lib/http-proxy.js:4:17)
>>     at Module._compile (module.js:460:26)

[williamhbutt]

Please merge ASAP. This caused my team some serious frustration. Thanks.