api snapshot public_url bugfix

with the following code the URL is more appropriate (it basically
mirrors the user's request)

before:

    http://localhost/device/{shortid}

after

    http://localhost:8000/device/{shortid}

api/views.py

@@ -1,6 +1,5 @@
 import json
 
-from django.conf import settings
 from django.urls import reverse_lazy
 from django.shortcuts import get_object_or_404, redirect
 from django.utils.translation import gettext_lazy as _