Make expansion work when parsed for null as well.

[BlitzOffline]

From what I can see there is no need for the expansion to require offline player and it looks quite easy to make it work with null players. From what I can tell you just have to remove the null checks and in the evaluate method you add some extra checks when adding the bindings for offline player since PlaceholderAPI#setPlaceholders and #setBracketPlaceholders both work with null.