Pull request: all: imp shell code

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

Squashed commit of the following:

commit 212f03f3d6e0824428c28ffd79cac8f5ea271d9c
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Fri Apr 9 14:51:59 2021 +0300

    all: imp shell code

bamboo-specs/release.yaml

@@ -200,7 +200,7 @@
         set -e -f -u -x
 
         export CHANNEL="${bamboo.channel}"
-        if [ "$CHANNEL" != 'release' -a "${CHANNEL}" != 'beta' ]
+        if [ "$CHANNEL" != 'release' ] && [ "${CHANNEL}" != 'beta' ]
         then
               echo "don't publish to Github Releases for this channel"