Fix the rendering of the API token

app/Resources/FOSUserBundle/views/Profile/show.html.twig

@@ -9,7 +9,7 @@
 
         <div class="input-group api-token-group clearfix">
             <input id="api-token" type="text" class="form-control" value="" data-api-token="{{ app.user.apiToken }}" readonly="readonly">
-            <span class="input-group">
+            <span class="input-group-btn">
                 <button class="btn btn-success btn-show-api-token" type="button">{{ 'profile.show_api_token'|trans }}</button>
             </span>
         </div>