Close#1014
Squashed commit of the following:
commit 759248efc0587ff2f288996c47739e602c557a76
Author: Simon Zolin <s.zolin@adguard.com>
Date: Thu Dec 12 19:26:46 2019 +0300
support empty ServerName
commit 68afecd5eca5ae66262b12dcb414b50efe88dc02
Author: Simon Zolin <s.zolin@adguard.com>
Date: Wed Dec 11 14:40:22 2019 +0300
+ DNS: TLS handshake: terminate handshake on bad SNI