[Gameplay] [TeamFight Tatics] Frozen Mallet stays on sejuani

Frozen Mallet (gives glacial attribute) stays on Sejuani who already has glacial attribute, instead of popping off to be used on a different champion.

1. Craft Frozen Mallet on Sejuani.

I don't know if this applies to other champions with the Glacial Attribute. Sejuani with Frozen Mallet.