fixed infolabel constraint, because it was covered by iphone action bar

deltachat-ios/Controller/QrCodeReaderController.swift

@@ -95,8 +95,9 @@ class QrCodeReaderController: UIViewController {
         videoPreviewLayer.frame = view.layer.bounds
         view.addSubview(infoLabel)
         infoLabel.translatesAutoresizingMaskIntoConstraints = false
-        view.addConstraint(infoLabel.constraintAlignBottomTo(view, paddingBottom: 8))
-        view.addConstraint(infoLabel.constraintCenterXTo(view))
+
+        infoLabel.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
+        infoLabel.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor, constant: 0).isActive = true
         view.bringSubviewToFront(infoLabel)
     }
 

deltachat-ios/Controller/QrViewController.swift

@@ -131,14 +131,12 @@ class QrViewController: UITableViewController, QrCodeReaderDelegate {
 
     //QRCodeDelegate
     func handleQrCode(_ code: String) {
-        //remove qr code scanner view
-        if let ctrl = navigationController,
-            let lastController = ctrl.viewControllers.last {
-                if type(of: lastController) === QrCodeReaderController.self {
-                    ctrl.viewControllers.removeLast()
-                }
+        qrCodeReaderController.dismiss(animated: true) {
+            self.processQRCode(code)
         }
+    }
 
+    private func processQRCode(_ code: String) {
         let qrParsed: DcLot = self.dcContext.checkQR(qrCode: code)
         let state = Int32(qrParsed.state)
         switch state {
@@ -204,7 +202,6 @@ class QrViewController: UITableViewController, QrCodeReaderDelegate {
             alert.addAction(UIAlertAction(title: String.localized("ok"), style: .default, handler: nil))
             present(alert, animated: true, completion: nil)
         }
-
     }
 
     private func joinSecureJoin(alertMessage: String, code: String) {