Issue recurring

It is illogical to have more than one in-place recurrence: different start/due dates cannot be applied to single issue and in-place recurrence does not create additional issues.

Also it is impossible to create meaningful algorithm to choose order for applying multiple different in-place recurrences without additional information. Just picking the earliest recurrence may be solution, but it's hard to come up with some real world application of something like that.

Until some good reason will be found for enabling it again (preferably through switch in plugin settings), it should be disabled to avoid misleading users creating multiple in-place recurrences, hoping it will work in any reasonable way.