Pull request: beta client on development channel

Merge in DNS/adguard-home from beta-client-channels to master

Squashed commit of the following:

commit c65611c1743aedd14779c95ed587330aff611b1d
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Mon Jan 11 14:09:21 2021 +0300

    home: activate beta client on development channel by default

internal/home/config.go

@@ -177,7 +177,7 @@ func initConfig() {
 	config.DHCP.Conf4.ICMPTimeout = 1000
 	config.DHCP.Conf6.LeaseDuration = 86400
 
-	if updateChannel == "none" || updateChannel == "edge" {
+	if updateChannel == "none" || updateChannel == "edge" || updateChannel == "development" {
 		config.BetaBindPort = 3001
 	}
 }