- clients: fix incorrect info for clients from /etc/hosts

Close #1786

Squashed commit of the following:

commit fc662252be38f20c9afda46fcb578efa50c9baf2
Author: Simon Zolin <s.zolin@adguard.com>
Date:   Thu Jun 11 10:57:26 2020 +0300

    - clients: fix incorrect info for clients from /etc/hosts

util/auto_hosts_test.go

@@ -49,10 +49,9 @@ func TestAutoHostsResolution(t *testing.T) {
 
 	// Test hosts file
 	table := ah.List()
-	ips, _ = table["host"]
-	assert.NotNil(t, ips)
-	assert.Equal(t, 1, len(ips))
-	assert.Equal(t, "127.0.0.1", ips[0].String())
+	name, ok := table["127.0.0.1"]
+	assert.True(t, ok)
+	assert.Equal(t, "host", name)
 
 	// Test PTR
 	a, _ := dns.ReverseAddr("127.0.0.1")