Pull request: scripts: imp all

Merge in DNS/adguard-home from imp-sh to master

Squashed commit of the following:

commit d574deae73e5c07e1e9ef43152de8d86b276c623
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Jun 10 20:00:56 2021 +0300

    scripts: imp all

scripts/make/build-docker.sh

@@ -14,9 +14,9 @@ fi
 set -e -f -u
 
 # Require these to be set.  The channel value is validated later.
-channel="$CHANNEL"
-commit="$COMMIT"
-dist_dir="$DIST_DIR"
+channel="${CHANNEL:?please set CHANNEL}"
+commit="${COMMIT:?please set COMMIT}"
+dist_dir="${DIST_DIR:?please set DIST_DIR}"
 readonly channel commit dist_dir
 
 if [ "${VERSION:-}" = 'v0.0.0' ] || [ "${VERSION:-}" = '' ]