Permit disabling the new loading screen

[Anaminus]

The problem has always been there:

PlayerGui defeats purpose of RemoveDefaultLoadingScreen

Some background: A LoadingScript displays a loading GUI while objects are being replicated from the server to the client. By default, this GUI is removed once the conditions that fire game.Loaded are met. If there are objects under ReplicatedFirst, then this GUI will be removed 5 seconds after ReplicatedFirst finishes (specifically, the conditions that fire ReplicatedFirst.FinishedReplicating). This GUI can be removed early by calling RemoveDefaultLoadingScreen. The earliest way to call this f…