webif: Redirect to correct IP if necessary

[derf]

When a user first connects to intercensor and opens a website, they are redirected to the Web IF, e.g. with the hostname google.com. When they then start a challenge and try to enter a solution, fuckup ensues.

Solution: When the webif is used with a hostname != 10.253.178.1, redirect to the correct IP first.

[mxey]

Several ideas have come up to fix this confusion:

• Disable the hijacking of all requests on no-challenge to prevent the confusion
• or actually redirect
• Register a domain (box.intercensor.org) for the game interface that is not part of the local zone