Fixed
* Crash when SQL errors occur while using the completion.
* Crash when cancelling a download prompt started in an already
closed window.
* Crash when many prompts are opened at the same time.
* Running without Qt installed now displays a proper error again.
* High CPU usage when using the keyhint widget with a low delay.
OBS-URL: https://build.opensuse.org/package/show/network/qutebrowser?expand=0&rev=67