Switching from Subdirectory to subdomain

When I first setup my Multisite Wordpress I chose a subdirectory install. I have switched to a Subdomain install and everything appears to be working. The only thing I havent been able to change is the DOMAIN_CURRENT_SITE line in wp-config.php.

According to the documentation for a Subdomain site it should be
define('DOMAIN_CURRENT_SITE', 'mydomain.com');

However, when I initially setup the Subdirectory site it was:
define('DOMAIN_CURRENT_SITE', 'www.mydomain.com');

Now when I try to change it to remove the "www." I get into a Wordpress redirect loop, so I have to add it back in.

Everything seems to work fine with the www. defined, but is this something I need to worry about?

Thanks