ci: fix wget error downloading arm-gcc-embedded
ci: fix wget error downloading arm-gcc-embedded

Disable certificate verification for developer.arm.com to avoid
certificate issues when installing arm embedded tools to build Mynewt.

Signed-off-by: Fabio Utzig <66676b1ceaf93296e098708c09494361103aa635@apache.org>

ATmobica/mcuboot,runtimeco/mcuboot,ATmobica/mcuboot,ATmobica/mcuboot,runtimeco/mcuboot,ATmobica/mcuboot,runtimeco/mcuboot,ATmobica/mcuboot,runtimeco/mcuboot,runtimeco/mcuboot