Merge pull request #160 in DNS/adguard-dns from fix/597 to master

* commit '53d680a5dfb027831bdbfc91bde5272d4d849a1a':
  Fix #597 - [bugfix] querylog_top: Empty domain gets to the Top Queried domains

dnsforward/querylog_top.go

@@ -9,8 +9,8 @@ import (
 	"sync"
 	"time"
 
-	"github.com/bluele/gcache"
 	"github.com/AdguardTeam/golibs/log"
+	"github.com/bluele/gcache"
 	"github.com/miekg/dns"
 )
 
@@ -158,6 +158,11 @@ func (d *dayTop) addEntry(entry *logEntry, q *dns.Msg, now time.Time) error {
 
 	hostname := strings.ToLower(strings.TrimSuffix(q.Question[0].Name, "."))
 
+	// if question hostname is empty, do nothing
+	if hostname == "" {
+		return nil
+	}
+
 	// get value, if not set, crate one
 	d.hoursReadLock()
 	defer d.hoursReadUnlock()