Fix UUID's in AsyncPlayerPreLoginEvent which are spoofed by BungeeCord.

When using ip-forward (and thus UUID forwarding) in Bungee, when Spigot fires AsyncPlayerPreLoginEvent the GameProfile which is used to populate the player name and UUID does not yet have the UUID present. 

This patch pulls the UUID from the NetworkManager object which already has the spoofed UUID when Spigot is configured with Bungee support.