Work around quirk in Fastmail

They seem to sort the parameters in an RRULE in a specific order, so
just use that by default to avoid any mismatch.

Author: Hugo Osvaldo Barrera

tests/storage/__init__.py

@@ -393,7 +393,7 @@ async def test_recurring_events(self, s, item_type):
         BEGIN:VEVENT
         DTSTART;TZID=UTC:20140128T083000Z
         DTEND;TZID=UTC:20140128T100000Z
-        RRULE:FREQ=WEEKLY;UNTIL=20141208T213000Z;BYDAY=TU
+        RRULE:FREQ=WEEKLY;BYDAY=TU;UNTIL=20141208T213000Z
         DTSTAMP:20140327T060506Z
         UID:{uid}
         CREATED:20131216T033331Z