Updates #3318. Squashed commit of the following: commit eebaa3ac3a6bfcb29e280006ead8ea9554b8a3bf Author: Ainar Garipov <A.Garipov@AdGuard.COM> Date: Tue Jul 6 14:59:00 2021 +0300 dnsforward: imp code commit 7591a3b183ab95f27f908267321518740cb7d4bb Author: Ainar Garipov <A.Garipov@AdGuard.COM> Date: Tue Jul 6 14:55:33 2021 +0300 dnsforward: fix panic