Set QR ec level

www/assets/js/addresscode.js

@@ -22,6 +22,7 @@ function getAddressQRCode() {
         scale: 5, // 3x scaling factor
         includetext: false, // Show human-readable text
         textxalign: 'center', // Always good to set this
+        eclevel: 'M'
     });
     document.getElementById("addresscode-barcode").src = canvas.toDataURL('image/png');