Fix string index

RIGS/views/rigboard.py

@@ -414,7 +414,7 @@ def post(self, request, *args, **kwargs):
         if not hmac.compare_digest(request.headers.get('X-Discourse-Event-Signature'), computed):
             return HttpResponseForbidden('Invalid signature header')
         body = simplejson.loads(request.body.decode('utf-8'))
-        event_id = int(body['topic']['title'][1:5]) # find the ID, force convert it to an int to eliminate leading zeros
+        event_id = int(body['topic']['title'][1:6]) # find the ID, force convert it to an int to eliminate leading zeros
         event = models.Event.objects.filter(pk=event_id).first()
         if event:
             event.forum_url = f"https://forum.nottinghamtec.co.uk/t/{body['topic']['slug']}"