Duplicate relations when creating single item relationship

[paulo-graca]

Describe the bug
I've executed the following in the video bellow at my local system and also managed to replicate at demo7.dspace.org. The issue is that when you try to create a single new relation, two new are created. And when try to save, an error occurs and only one remains.

To Reproduce
Steps to reproduce the behavior:

1. Using demo7.dspace.org
2. Having entities created
3. Then create a new relation...
   

Expected behavior
Since I only assign one relation, only one should be presented to the user. But a duplication is shown.

[tdonohue]

Thanks @paulo-graca . I can reproduce this locally. Not sure how it occurs.

Will mention this in tomorrow's Dev meeting.