fixed a bug at day-queries-service

I missed a replacement mishap in !239 and fixed it :D

But then I stumbled across another bug, closely related: Previously we referenced the defaultSchedule in QuestionRelations (formerly known as QuestionSchedules), where the QuestionRelation had no specific question of its own. The reason for that was, that when editing the schedules we accidentally edited the default Schedule. Now the DayQueriesService failed to find the appropriate Schedule, because it was looking at the QuestionRelations and found undefined. Therefore I introduced SymptomCheck.getEffectiveSchedule() that returns either the specific Schedule for a question or if need be a copy of the default schedule. That's it :)

@CRSchmidt can you take a look?

Closes #372 (closed)

changed milestone to %Things to be done some time before the end of May

assigned to @CRSchmidt

changed the description

requested review from @CRSchmidt

assigned to @rhotep and unassigned @CRSchmidt

changed the description

requested review from @james-jenkinson and removed review request for @CRSchmidt

@rhotep , @CRSchmidt has been off this week due to sickness, taking over the review

approved this merge request

Looks good

thanks :)

mentioned in commit 6cc56fb2

merged