Minor fix to make sk2 run on fedora

[patrickwalton]

On Fedora, SK2 didn't run for me. This single-line fix was suggested by AI and worked. Here's the summary from the AI:

The problem was that self.init_done wasn't initialized as an instance variable at the beginning of the __init__ method.

Here's what was happening:

1. The settings_create() method (called on line 91) connects UI widget signals to settings_save_needed()
2. Some of these signal connections could trigger immediately during the connection process
3. This would call settings_save_needed(), which tries to check if not self.init_done:
4. Since self.init_done didn't exist as an instance variable yet, this would fail
5. The method would continue and call self.update_status_bar()
6. But self.label_status_bar hadn't been created yet (that happens on line 93)

The fix was to initialize self.init_done = False at the very beginning of the __init__ method. This ensures that the protection check in settings_save_needed() works properly and prevents update_status_bar() from being called before the status bar label is created.