Fix #747

Author: damonmcminn

lib/http-proxy/common.js

@@ -80,7 +80,7 @@ common.setupOutgoing = function(outgoing, options, req, forward) {
   // Remark: Can we somehow not use url.parse as a perf optimization?
   //
   var outgoingPath = !options.toProxy
-    ? url.parse(req.url).path
+    ? (url.parse(req.url).path || '/')
     : req.url;
 
   outgoing.path = common.urlJoin(targetPath, outgoingPath);