scripts: always check certificates

scripts: always check certificates

Remove flags from wget and curl instructing them to ignore bad server
certificates. Although other mechanisms can protect against malicious
modifications of downloads, other vectors of attack may be available
to an adversary.

TLS certificate verification can be disabled by turning oof the
"Enable TLS certificate verification during package download" option
enabled by default in the "Global build settings" in "make menuconfig"

Signed-off-by: Josh Roys <roysjosh@gmail.com>
[ add additional info on how to disable this option ]
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Petr Štetiar <ynezz@true.cz> [backport]
(cherry picked from commit 90c6e3aedf167b0ae1baf376e7800a631681e69a)