Issue Summary

Jira imports from Trello boards no longer work. That seems to be because of a change in Trello security policies that were announced two months ago:

https://community.developer.atlassian.com/t/pure-wildcard-allowed-origins-on-app-keys-will-no-longer-be-recognized-and-will-be-fully-deprecated/52093

Steps to Reproduce

1. Go to Jira's External System Import
2. Select Trello and follow the steps

Expected Results

The Trello board and cards are imported to a Jira project

Actual Results

Error message:

Invalid return_url. Wildcard ("*") allowed origins are no longer supported. Contact the developer. See https://community.developer.atlassian.com/t/52093 

Workaround

There is no workaround, the External System Importer must be fixed