Cacher is the code snippet organizer for pro developers

In Extension Manager (EM) find the RealURL and set option Automatic configuration file format to PHP source (slow!) (with automatic conf still enabled!)
Remove the file typo3conf/realurl_autoconf.php (as far as I remember), clear all caches and refresh the main page, the autoconf file will be recreated in unserialized version.
Rename the file to typo3conf/realurl_conf.php, go to EM again and uncheck the automatic configuration option.
After clearing the caches and you'll be switched to manual config built from the automatic one.