Pull request: querylog: fix oldest calc

Updates #4591.

Squashed commit of the following:

commit 70b70c78c85311363535536c7ea12336b21accf8
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Wed May 25 17:35:54 2022 +0300

    querylog: fix oldest calc

internal/querylog/querylog.go

@@ -28,8 +28,11 @@ type QueryLog interface {
 	WriteDiskConfig(c *Config)
 }
 
-// Config - configuration object
+// Config is the query log configuration structure.
 type Config struct {
+	// Anonymizer processes the IP addresses to anonymize those if needed.
+	Anonymizer *aghnet.IPMut
+
 	// ConfigModified is called when the configuration is changed, for
 	// example by HTTP requests.
 	ConfigModified func()
@@ -68,9 +71,6 @@ type Config struct {
 	// AnonymizeClientIP tells if the query log should anonymize clients' IP
 	// addresses.
 	AnonymizeClientIP bool
-
-	// Anonymizer processes the IP addresses to anonymize those if needed.
-	Anonymizer *aghnet.IPMut
 }
 
 // AddParams is the parameters for adding an entry.
@@ -91,18 +91,18 @@ type AddParams struct {
 	// Result is the filtering result (optional).
 	Result *filtering.Result
 
-	// Elapsed is the time spent for processing the request.
-	Elapsed time.Duration
-
 	ClientID string
 
-	ClientIP net.IP
-
 	// Upstream is the URL of the upstream DNS server.
 	Upstream string
 
 	ClientProto ClientProto
 
+	ClientIP net.IP
+
+	// Elapsed is the time spent for processing the request.
+	Elapsed time.Duration
+
 	// Cached indicates if the response is served from cache.
 	Cached bool