Make redirect update in refreshLinks.php bypass the redirect table

Make redirect update in refreshLinks.php bypass the redirect table

This makes this script actually useful when updating namespaces by
making sure the target registred in the "redirect" is the correct one.

Consider the following example:

- Create a redirect page pointing to a page "Extra:Target"
- Add $wgExtraNamespaces[100] = 'Extra'; in LocalSettings.php
- run refreshLinks.php

Previously the redirect target of that page was not updated and still
pointing to (0, "Extra:Target") which no longer a valid title.
Now it will be updated correctly to point to (100, "Target").

The value of the page_is_redirect field will also be updated to be
sure it has the correct value, which might be wrong when the target
becomes valid or invalid, e.g. by changing $wgInvalidRedirectTargets.

Change-Id: I458ca63550df56ca96b35749daf4e7b866ab9d93