AI Assistant upgrade banner's `Open package Manager` link doesn't work

This happens on 2.6.0, Unity 6.0. when i tried to upgrade AIA version

Steps to reproduce:

1. Open project with older version of AIA installed
2. Open AIA window, see the banner
3. Click the Open Package Manager link

Actual results: Package Manager not Opened

Expected results: Package manager opens

Reproducible with versions: 2.6

Not reproducible with versions: 

Can’t test with versions: 2.7, as no new version to test.

Tested on (OS): 

Mac
Notes:

• At the same time, the link from the AI button works just fine.