"loading model" when typing while long auto completion list opens up

[mthiede]

test condition: backend started, model loaded

• invoke auto completion without a prefix which yields a lot of options (e.g. AR interface)
• while the list is not yet populated, start typing, e.g. "/Default"
• the list shows "loading model", although the model is not being reloaded (no backend crash)
• if you repeat this test without typing while the list is building up, everything is fine again