[cloud] Fix error shown to the user when org invite is declined

Created by: kopancek

Description

Fix error shown to the user when org invite is declined

Related Jira issue:

https://sourcegraph.atlassian.net/browse/CLOUD-154 https://sourcegraph.atlassian.net/browse/CLOUD-153

Related PR:

#28170

Testing locally

1. Run sg in cloud mode: sg start dotcom
2. Create an organization
3. Create an organization invite for another user
4. Login with the other user
5. Follow the invite link
6. Click on Decline
7. The user should be navigated to user settings