package/libcurl: security bump to 7.72.0

This new version fixes, amongst many other things, CVE-2020-8231
(https://curl.haxx.se/docs/CVE-2020-8231.html). See the full changelog
on https://curl.haxx.se/changes.html#7_72_0

 .

Also drop the 4 patches, that have all been released upstream.

Signed-off-by: Titouan Christophe <titouan.christophe@railnova.eu>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>