Uncancelled game bug fix

This bugfix corrects for the bug that was reported in the hai!touch Studios Discord server:

On the signup screen, the player started the game, and the game continued to download the missing question data. The bug was caused by the “Back” button being active while the “loading questions” pop-up was still visible. The game returned to the episode selection screen, then started the canceled game with the 5 default player slots.

The bug has been fixed by deactivating the “Back” button while the loading pop-up is visible.

In addition, the “Godot Engine” logo has been deleted from the startup splash screen to speed up boot. I don’t feel comfortable promoting Godot Engine after the recent social media disaster surrounding the mismanagement of Godot’s official social media and the “#Wokot” hashtag anyway.