kitty: Slightly decrease click_interval to 0.4

Kitty's source code makes me believe that this is always 0.5s on X11.
This decreases the delay when opening links.

Link: https://github.com/kovidgoyal/kitty/blob/3482d084aef1/glfw/x11_window.c#L2360-L2363

.config/kitty/kitty.conf

@@ -630,7 +630,7 @@ mouse_hide_wait -1
 #: If empty (default) select_by_word_characters will be used for both
 #: directions.
 
-# click_interval -1.0
+click_interval 0.4
 
 #: The interval between successive clicks to detect double/triple
 #: clicks (in seconds). Negative numbers will use the system default