Webhook.http_content_type to slug (#3569)

netbox/extras/choices.py

@@ -118,3 +118,23 @@ class ExportTemplateLanguageChoices(ChoiceSet):
         LANGUAGE_DJANGO: 10,
         LANGUAGE_JINJA2: 20,
     }
+
+
+#
+# Webhooks
+#
+
+class WebhookContentTypeChoices(ChoiceSet):
+
+    CONTENTTYPE_JSON = 'application/json'
+    CONTENTTYPE_FORMDATA = 'application/x-www-form-urlencoded'
+
+    CHOICES = (
+        (CONTENTTYPE_JSON, 'JSON'),
+        (CONTENTTYPE_FORMDATA, 'Form data'),
+    )
+
+    LEGACY_MAP = {
+        CONTENTTYPE_JSON: 1,
+        CONTENTTYPE_FORMDATA: 2,
+    }