Fix calls to reverse

wagtailvideos/wagtail_hooks.py

 from django.conf.urls import include, url
 from django.contrib.staticfiles.templatetags.staticfiles import static
-from django import urls
+from django.urls import reverse
 from django.utils.html import format_html, format_html_join
 from django.utils.translation import ugettext_lazy as _
 from wagtail.admin.menu import MenuItem
@@ -32,7 +32,7 @@ def editor_js():
             window.chooserUrls.videoChooser = '{0}';
         </script>
         """,
-        urls.reverse('wagtailvideos:chooser')
+        reverse('wagtailvideos:chooser')
     )
 
 
@@ -44,6 +44,6 @@ def register_video_permissions_panel():
 @hooks.register('register_admin_menu_item')
 def register_images_menu_item():
     return MenuItem(
-        _('Videos'), urls.reverse('wagtailvideos:index'),
+        _('Videos'), reverse('wagtailvideos:index'),
         name='videos', classnames='icon icon-media', order=300
     )