qutebrowser: Set tab display length to 2 seconds

When not showing tabs (only displaying them on actually
switchting between tabs), so far the duration that the
tabs would be displayed was just 800ms, way too short
to actually provide legible info.

This commit changes it to 2000ms, which may still be
too short but is at least more digestible.

qutebrowser/.config/qutebrowser/config.py

@@ -56,6 +56,7 @@ c.tabs.title.format = "{index} {audio}{perc}{current_title}"
 c.tabs.position = "right"
 c.tabs.width = "15%"
 c.tabs.show = "multiple"
+c.tabs.show_switching_delay = 2000
 c.statusbar.show = "always"
 
 c.colors.webpage.bg = "#555555"