KCC: Comment about schedule types

Signed-off-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
Reviewed-by: Garming Sam <garming@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

python/samba/kcc_utils.py

@@ -1123,6 +1123,8 @@ class NTDSConnection(object):
         """Returns True if our schedule includes at least one
         replication interval within the week.  False otherwise
         """
+        # replinfo schedule is None means "always", while
+        # NTDSConnection schedule is None means "never".
         if self.schedule is None or self.schedule.dataArray[0] is None:
             return False