compare service id to UUID

it doesn't match a string 😩
I couldn't think of a good way to test this in a unit test, since
it involves changing the service id on all of the components of a
service.

app/celery/letters_pdf_tasks.py

@@ -1,3 +1,4 @@
+from uuid import UUID
 import math
 from datetime import datetime
 
@@ -187,7 +188,7 @@ def process_virus_scan_passed(self, filename):
     new_pdf = _sanitise_precomiled_pdf(self, notification, old_pdf)
 
     # TODO: Remove this once CYSP update their template to not cross over the margins
-    if notification.service_id == 'fe44178f-3b45-4625-9f85-2264a36dd9ec':  # CYSP
+    if notification.service_id == UUID('fe44178f-3b45-4625-9f85-2264a36dd9ec'):  # CYSP
         # Check your state pension submit letters with good addresses and notify tags, so just use their supplied pdf
         new_pdf = old_pdf