staging: comedi: adv: Replace HTTP links with HTTPS ones

Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Link: https://lore.kernel.org/r/20200723191827.72047-1-grandmaster@al2klimov.de


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>