How to disable SSO on WP multisite?

Hi there,
Looking at this issue I have -pingdom report-: https://premium.wpmudev.org/forums/topic/admin-ajaxphpactiondomainmap-setup-cdsso-impacting-performance
I'm trying to find the way to disable SSO on my wp multisite install, but it seems to be hidden somewhere and google is confusing me more than anything else.

Please advise,
Julien