Activate newly added association rules for UML2 "required interface"

Fixup of commit 48ae6b8ec83505a22cdc8811feeafa3040db13a7.

(cherry picked from commit 0514f21fbc66e54a3afb8e91d89e38b127ac1ff2)

CCBUG:115269
BUG:403808
FIXED-IN:2.29.0 (KDE Applications 19.08.0)