Update django.plugin.zsh

activate django plugin on command "django-admin"

plugins/django/django.plugin.zsh

@@ -236,5 +236,6 @@ _managepy() {
 
 compdef _managepy manage.py
 compdef _managepy django
+compdef _managepy django-admin
 compdef _managepy django-admin.py
 compdef _managepy django-manage