package/wayland: switch to https

package/wayland: switch to https

--2020-06-07 20:39:28--  http://wayland.freedesktop.org/releases/wayland-1.18.0.tar.xz
Resolving wayland.freedesktop.org (wayland.freedesktop.org)... 35.227.58.183
Connecting to wayland.freedesktop.org (wayland.freedesktop.org)|35.227.58.183|:80... connected.
HTTP request sent, awaiting response... 308 Permanent Redirect
2020-06-07 20:39:29 ERROR 308: Permanent Redirect.

Fixes:
 - http://autobuild.buildroot.org/results/f3af97ad46830568ee3ad710fe45329f7626c27b

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>