title: swift decimal format to double format issue
body: <p>I have a textfield where I can write the an decimal-keypad a value like <code>25.00</code>
  This value I save into CoreData (double format) =&gt; <code>Double(txtField.text!)!</code>
  It works !</p>
  <p>On an device, which is set to &quot;Germany&quot;, the value Wille be <code>25,00</code>
  But there I will get this error:</p>
  <pre><code>Fatal error: Unexpectedly found nil while unwrapping an Optional value
  </code></pre>
  <p>(swift 5)</p>
  <p>Where is my mistake?
  Thanks !</p>