Some new items are getting incorrect item level

This is due to a bonusid type of 51:

```
# Sunwell Defender's Brooch (120)
neck=,id=251076,bonus_id=13573
```

`[251076] [13573:51] Unknown bonus entry: 51 (13573): {"Id":30300,"BonusId":13573,"Type":51,"Value1":174,"Value2":300,"Value3":0,"Value4":0,"Index":0}`

This item defaults to ilvl 415, and should be reduced by the bonus_id (presumably) down to 120.

