Network requests hangs with cache written by older Qt version

If the network cache is written with Qt 5.1.1, program built with Qt 5.2.0 cannot use this cache properly and hangs on network requests.

To reproduce:
1. Build program with Qt 5.1.1 and run it.
2. You should see message in the console.
3. Then build with Qt 5.2.0 and run.
4. No message, network request is hanging.