fix (jans-tarp): agama Lab's tab closing automatically if same window has tarp opened

[duttarnab]

Steps to reproduce the issue:

1. Open jans-tarp in an incognito window of the Chrome browser.
2. Complete some auth flow using trap leading to the display of User Info page
3. Open another tab on the same window and try to login to agama-lab.
4. The tab automatically closes after agama-lab is logged in.