api_entreprise: removes dead import (#33056)

passerelle/apps/api_entreprise/models.py

@@ -25,7 +25,7 @@ import requests
 from django.db import models
 from django.utils.translation import ugettext_lazy as _
 from django.utils.timezone import datetime, make_aware, timedelta
-from django.http import HttpResponse, Http404, HttpResponseBadRequest
+from django.http import HttpResponse, Http404
 from django.core import signing
 from django.core.urlresolvers import reverse