Fix #831

This commit fixes panic when customDialContext fails to resolve the host's address.

home/config.go

@@ -126,6 +126,7 @@ type tlsConfig struct {
 }
 
 // initialize to default values, will be changed later when reading config or parsing command line
+// TODO: Get rid of global variables
 var config = configuration{
 	ourConfigFilename: "AdGuardHome.yaml",
 	BindPort:          3000,