Fix boss keys being shuffled when they shouldn't be

[cjohnson57]

If the following conditions were true:

• Key rings were on for a dungeon
• Key rings were set to give boss keys
• Small keys were set to own dungeon or keysy

Then the boss keys would still be shuffled into the item pool, even though they shouldn't be.

As vanilla overrides the key ring setting, it's correct to still shuffle the BK in this case. However, dungeon and remove were excluded from this as well. You could argue that it makes sense to still shuffle the BKs under remove since BKs have their own keysy setting, but under current behavior you'll still start with the BK in this situation, so it doesn't make sense to also shuffle it. I changed both times this is checked for (for the base and plentiful item pool) to specifically check for vanilla.