For keyboard navigation the highlightResult() function in keyboard.js steals the
focus. On a mouse click event (non keyboard action) the focus should resist
where it is, otherwise a marked region gets lost. This is the reason why text
can't be selected when using simple theme with JS enabled.
Closes: https://github.com/searxng/searxng/issues/794
Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>