Jira site import does not allow email addresses with characters like + and ' in the backup file

Issue Summary

Jira import process does not allow + and ' in the email addresses during the validation phase.

Steps to Reproduce

1. Create a test Cloud/Server Jira instance.
2. Create a user in the site with email something like abc+xy'z@gmail.com
3. Create a backup of this instance.
4. Submit this backup in another Jira Cloud site.

Expected Results

Jira importer should not throw errors for emails with + and ' in them.

Actual Results

Jira importer shows a window to correct such emails and remove + and ' from them and if we will skip this part, the import will fail.

Workaround

NA

Notes:

• + and ' are actually valid aliases/characters for an email address.
• A month ago, Jira import used to accept such emails, this change came into action this month only.
• If the site allows inviting such emails then it should also accept such emails in Jira import validation also.