Fix bug when POST'ing filter form data to edit schedule page

tailbone/views/shifts/schedule.py

@@ -60,6 +60,9 @@ class ScheduleView(TimeSheetView):
                         if uuid:
                             data[field][uuid] = self.request.POST[key]
 
+            # if no fields, don't apply changes (filter form uses POST also)
+            if any(data.itervalues()):
+
                 # apply delete operations
                 deleted = []
                 for uuid, value in data['delete'].iteritems():