Merge pull request #439 from OrangeSofter/fix_assert

Assert fixed

lib/src/qr_scanner_overlay_shape.dart

@@ -22,7 +22,7 @@ class QrScannerOverlayShape extends ShapeBorder {
       "Border can't be larger than ${min(this.cutOutWidth, this.cutOutHeight) / 2 + borderWidth * 2}",
     );
     assert(
-        (cutOutSize != null && cutOutWidth == null && cutOutHeight == null) ||
+        (cutOutWidth == null && cutOutHeight == null) ||
             (cutOutSize == null && cutOutWidth != null && cutOutHeight != null),
         'Use only cutOutWidth and cutOutHeight or only cutOutSize');
   }