Fix empty username

Author: codefiles

archinstall/lib/interactions/manage_users_conf.py

@@ -78,6 +78,9 @@ def _add_user(self) -> User | None:
 			case _:
 				raise ValueError('Unhandled result type')
 
+		if not username:
+			return None
+
 		header = f'{tr("Username")}: {username}\n'
 
 		password = get_password(tr('Password'), header=header, allow_skip=True)