Remove incorrect comment.

Those are really calendar weeks (although starting on monday independently
from locale) as it is less expensive to compute them accurately for table
precision than for graph precision (much fewer dates to convert).

apachedex/__init__.py

@@ -915,7 +915,7 @@ period_parser = {
     # Error margin without correction: (DST) 1/24 = 4%
     lambda x: 1,
   ),
-  'week': ( # XXX: should be "7 days", but a single word is more convenient
+  'week': (
     _as6HourString,
     _hourAsWeekString,
     '6 hours',