Second specimen tube is not linked if registered before pathology referral

[Nicklas Nordborg]

This may be a rather exotic case:

1. Register a core-biopsy specimen tube (with 'C' suffix).
2. Register a regular specimen tube with the same case name (without 'C' suffix).
3. Register the pathology referral form for the core-biopsy specimen.
4. Register the pathology referral form for the regular specimen.

The end result is that one case and two specimen tubes are created. But only the first specimen tube is linked with the case. The second specimen tube is without a parent. Updating the registration of the pathology referral form does not help.

Already registered specimen tubes must be fixed by hand.

In most cases there is usually a month or more between 1 and 2 which means that 3 is usually performed before 2 and then everything works.

[Nicklas Nordborg]

(In [2600]) Fixes #621: Second specimen tube is not linked if registered before pathology referral