Tier bonus set is not applied when items have transmog

[abracadaniel22]

Steps to reproduce:

• Equip two tier pieces
  • for example: Crystalforge Faceguard + Crystalforge Handguards
  • or another example: Justicar Shoulderguards + Justicar Chestguard
• Verify that the bonus for equipping two pieces is applied:
  • 
• Now apply a transmog to any of those items, or both

Expected result:

• The set bonus is not removed

Actual result:

• The set bonus is removed
  •