Make "Live update" window closeable via ESC key

Hi,

In general I want to be informed when a new version was released. But sometimes when I start FlashFXP, I just want to use the FlashFXP version which is currently installed and don't have the time to update

When FlashFXP starts and finds an update, the "Live Update" window will be shown. I wish I would be able to close that window just by pressing the ESC key... understand me?

Sure, we can incorporate this change into the next release.