Obsolete conntrack in fw3 but still present in Omnia repo?

Turris Omnia - rtrom01
Turris OS 3.9.6
Kernel 4.4.119-082ea0f4a4e204b99821bedcb349ed54-0

It seems that conntrack been removed from fw3 by 14 Dec 2016 and thus being obsolete but still being present in the Omnia repo?

Having it set to option conntrack '1' produces

Warning: Option @zone[0].conntrack is unknown