GNOME Shell extensions have a UUID property; this key lists extensions which should be disabled, even if loaded as part of the current mode. You can also manipulate this list with the EnableExtension and DisableExtension D-Bus methods on org.gnome.Shell. This key takes precedence over the “enabled-extensions” setting.
EnglishTTLS and PEAP are actually much more complicated, but this complication
is not visible here since we only care about phase2 authentication
(and don't even care of which one)