Update the interwiki cache

The interwiki cache is a cache of meta:Interwiki map, which maps interwiki prefixes to URLs

This is how it appears to be updated:

cd /home/wikipedia/common/php-1.5/maintenance
php dumpInterwiki.php -o /home/wikipedia/common/php-1.5/cache/interwiki.cdb
sync-file cache/interwiki.cdb Updating interwiki cache for new wikitech entry