A small bug

Hi, great plugin thank you.

I found a small bug. For example, if there is a user with saved city as a “test” for example. And then we install this plugin which takes saved value city “test” and then match with existing cities it will fail with php error:

Notice: Undefined index: test in /***/wp-content/plugins/wc-city-select/wc-city-select.php on line 133

Warning: Invalid argument supplied for foreach() in /***/wp-content/plugins/wc-city-select/wc-city-select.php on line 141

It is not a fatal error and plugin works as it should but can you fix it please. Thank you.