Rejuvenation Ring doesn't heal after performing an attack.

Reproduction steps:
1. Deploy a champion.
2. Wound it.
3. Equip it with Rejuvenation Ring.
4. The equipped champion will not heal after attacking, but regains 3 HP at the beginning of each turn.
5. Rejuvenation Ring states it restores 3 HP after performing an attack, so clearly this is a bug.

@Sokolov