Canot call method 'split' of null

Created by: Rush

After recent upgrade my tests break:

Uncaught TypeError: Cannot call method 'split' of null
    at Object.common.urlJoin (/code/http-master/node_modules/http-proxy/lib/http-proxy/common.js:142:23)
    at Object.common.setupOutgoing (/code/http-master/node_modules/http-proxy/lib/http-proxy/common.js:75:26)
    at Array.stream [as 3] (/code/http-master/node_modules/http-proxy/lib/http-proxy/passes/web-incoming.js:109:14)
    at ProxyServer.<anonymous> (/code/http-master/node_modules/http-proxy/lib/http-proxy/index.js:80:21)
    at Object.ProxyMiddleware.requestHandler (/code/http-master/modules/middleware/proxy.js:9:4607)