I just pushed yet another update (1.2.3, v14/v7) that makes the damn client check a php file instead of a txt file when confirming the version number!
Turns out Godot will cache a txt file and then not update the thing whose only purpose is to let you know when it has been updated! Whoops.
Please update and restart your game at your earliest convenience, just so your game will let you know when there's a new version.