calendar: add missing translatable label for module (#16962)

combo/apps/calendar/__init__.py

@@ -15,10 +15,12 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import django.apps
+from django.utils.translation import ugettext_lazy as _
 
 
 class AppConfig(django.apps.AppConfig):
     name = 'combo.apps.calendar'
+    verbose_name = _('Calendar')
 
     def get_before_urls(self):
         from . import urls