[test] Remove terminate-when-inactive behavior from the test server

It caused #3163.

Attempts at having the child exit automatically when the parent exits were stymied
by the fact that unix sucks: http://stackoverflow.com/q/284325/52207.

test/storage/server.js

@@ -9,19 +9,6 @@ var app = express();
 // We're manually setting Etag headers.
 app.disable('etag');
 
-// Terminate after a certain time of inactivity.
-function terminate() {
-    console.warn('Server terminated due to inactivity');
-    process.exit(0);
-};
-var inactivity = 5000; // milliseconds
-var timeout = setTimeout(terminate, inactivity);
-app.use(function(req, res, next) {
-    clearTimeout(timeout);
-    timeout = setTimeout(terminate, inactivity);
-    next();
-});
-
 app.get('/test', function (req, res) {
     if (req.query.modified) {
         res.setHeader('Last-Modified', (new Date(req.query.modified * 1000)).toUTCString());