fix(warp): surface update-clock persistence failures (#6209)

Co-authored-by: n0ctal <293235942+n0ctal@users.noreply.github.com>

internal/web/service/setting.go

@@ -391,11 +391,17 @@ func (s *SettingService) setInt(key string, value int) error {
 }
 
 func (s *SettingService) GetWarpLastUpdate() (int64, error) {
-	val, err := s.getString("warpLastUpdate")
-	if err != nil || val == "" {
+	setting, err := s.getSetting("warpLastUpdate")
+	if database.IsNotFound(err) {
+		return 0, nil
+	}
+	if err != nil {
 		return 0, err
 	}
-	return strconv.ParseInt(val, 10, 64)
+	if setting.Value == "" {
+		return 0, nil
+	}
+	return strconv.ParseInt(setting.Value, 10, 64)
 }
 
 func (s *SettingService) SetWarpLastUpdate(val int64) error {