main/gnutls: security upgrade to 3.6.15

- CVE-2020-24659

(cherry picked from commit 1c38dfee)
7 jobs for !12092 with 3.9-gnutls in 38 minutes and 20 seconds (queued for 12 seconds)
detached
Status Job ID Name Coverage
  Lint
passed #199886
docker-alpine x86_64
lint

00:01:56

 
  Build
passed #199891
docker-alpine ci-build aarch64
build-aarch64

00:05:18

passed #199892
docker-alpine ci-build armv7
build-armv7

00:07:37

passed #199890
docker-alpine ci-build ppc64le
build-ppc64le

00:16:42

passed #199889
s390x docker-alpine ci-build
build-s390x

00:02:14

passed #199888
docker-alpine ci-build x86
build-x86

00:04:11

passed #199887
docker-alpine ci-build x86_64
build-x86_64

00:04:11