Fix deprecation warning

src/pretix/base/forms/__init__.py

@@ -167,6 +167,7 @@ class SettingsForm(i18nfield.forms.I18nFormMixin, HierarkeyForm):
 
 class PrefixForm(forms.Form):
     prefix = forms.CharField(widget=forms.HiddenInput)
+    template_name = "django/forms/table.html"
 
 
 class SafeSessionWizardView(SessionWizardView):

src/pretix/base/templates/pretixbase/email/base.html

@@ -86,6 +86,11 @@
             hyphens: auto;
         }
 
+        p a {
+            word-wrap: anywhere;
+            word-break: break-all;
+        }
+
         .footer {
             padding: 10px;
             text-align: center;