fix invalid focal_point attribute on image edit view

wagtail/images/templates/wagtailimages/images/edit.html

@@ -80,7 +80,7 @@
                 <div class="row">
                     <div class="col8 divider-after">
                         <h2 class="label no-float u-text-transform-uppercase">{% trans "Focal point" %} <span class="u-text-weight-normal">{% trans "(optional)" %}</span></h2>
-                        <p>{% trans "To define this image's most important region, drag a box over the image above." %} {% if image.focal_point %}({% trans "Current focal point shown" %}){% endif %}</p>
+                        <p>{% trans "To define this image's most important region, drag a box over the image above." %} {% if image.has_focal_point %}({% trans "Current focal point shown" %}){% endif %}</p>
 
                         <button class="button button-secondary no remove-focal-point" type="button">{% trans "Remove focal area" %}</button>
                     </div>