Bug: RNA delivery messages are repetitive

[karlnyr]

Describe the bug

When I copy a delivery message for an RNA case that has multiple samples in it that is targeting the same case I get repetitive information. See the attached message generated for a case:

​Hello,

The analysis for case case-RNA has been uploaded to the corresponding DNA case(s) on Scout at:

https://scout.scilifelab.se/customer/case_a
https://scout.scilifelab.se/customer/case_b
https://scout.scilifelab.se/customer/case_c-trio
https://scout.scilifelab.se/customer/case_c-trio
https://scout.scilifelab.se/customer/case_c-trio

To Reproduce
Steps to reproduce the behavior:

1. Go to trailblazer and copy the delivery message for case amplegrubworm

Expected behavior

We do not give repetitive information in our delivery messages.