Add missing param

webhook/views.py

@@ -1,15 +1,16 @@
 import logging
-import stripe
 
+import stripe
 # Create your views here.
 from django.conf import settings
 from django.http import HttpResponse
 from django.views.decorators.csrf import csrf_exempt
 from django.views.decorators.http import require_POST
 
-from membership.models import StripeCustomer
 from hosting.models import MonthlyHostingBill, HostingBillLineItem
+from membership.models import StripeCustomer
 from utils.tasks import send_plain_email_task
+
 logger = logging.getLogger(__name__)
 
 
@@ -110,7 +111,7 @@ def handle_invoice_webhook(request):
     elif event.type == "invoice.payment_failed":
         logger.error("Invoice payment failed")
 
-        admin_msg_sub = "Invoice payment FAILED for user {} and ".format(
+        admin_msg_sub = "Invoice payment FAILED for user {} and {}".format(
             stripe_customer.user.email,
             invoice.lines.data.metadata
         )