Added form_category to the ticket payload if existing

This resolves #203.

cgi-bin/form.py

@@ -345,12 +345,8 @@ try:
 		assert isinstance(customer_id, (str, int))
 
 	# Add the actual ticket to the system.
-	response = session.post(
-		urljoin(ZAMMAD_URL, "api/v1/tickets"),
-		headers={
-			"From": contact_email,
-		},
-		json=dict(
+
+	ticket_payload=dict(
 		title=f"Kontaktformular {contact_name} – {form_name}",
 		group=form_group,
 		customer_id=customer_id,
@@ -366,7 +362,16 @@ try:
 				"mime-type": mimetypes.guess_type(attachment[0])[0] or "text/plain",
 			}],
 		),
-		),
+	)
+	if form_category:
+		ticket_payload["category"] = form_category
+
+	response = session.post(
+		urljoin(ZAMMAD_URL, "api/v1/tickets"),
+		headers={
+			"From": contact_email,
+		},
+		json=ticket_payload,
 	)
 	response.raise_for_status()
 	ticket_id = response.json()["id"]