adapt string formatting

deltachat-ios/Controller/GroupChatDetailViewController.swift

@@ -116,7 +116,8 @@ extension GroupChatDetailViewController: UITableViewDelegate, UITableViewDataSou
     func tableView(_: UITableView, viewForHeaderInSection section: Int) -> UIView? {
         if section == sectionConfig {
             let header = ContactDetailHeader()
-            header.updateDetails(title: chat.name, subtitle: String.localizedStringWithFormat(NSLocalizedString("n_members", comment: ""), chat.contactIds.count))
+            header.updateDetails(title: chat.name,
+                                 subtitle: String.localizedStringWithFormat(String.localized("n_members"), chat.contactIds.count))
             if let img = chat.profileImage {
                 header.setImage(img)
             } else {