ExecutableFileOpenDialog: Make "Dont ask again" clearer
Tell the user what the option does and that it applies to all executable files.
Since the GUI for this setting is in Dolphin and not KIO, when Dolphin is the default file manager (real-world Plasma session), a hint is shown how the user can undo this choice.
Unfortunately it seems the GUI to revert this is only in Dolphin and not in a KIO KCM, otherwise it would be nice to tell the user how to unremember it. (added a hint, see comment below)
Edited by Kai Uwe Broulik