title: NSLocaleGroupingSeparator returns empty space instead of apostrophe since iOS 11 (Swiss / German locale)
body: <p>In my Calculator app I use the system's call to the character to use for display grouping (a.k.a thousands separator).</p>
  
  <pre><code>[[NSLocale currentLocale] objectForKey:NSLocaleGroupingSeparator];
  </code></pre>
  
  <p>For iOS 9,10 in German and Swiss regional locales I got an apostrophe (which seems correct to me). Since iOS 11 it returns an empty space. Other locales that use either dots or commas as thousands separators are still fine.</p>
  
  <p>So on iOS 9/10 I get:
  10'000'000</p>
  
  <p>And on iOS 11 I get this:
  10 000 000</p>
  
  <p>Any idea? Did some official rule change ? Swiss / German customers are definitely not happy with the chance.</p>