The reply-to is not respecting the request-type that dont have a Mail Channel

Issue Summary

This is reproducible on Data Center: yes

Steps to Reproduce

1. Create a JSM project
2. Configure one Mail Channel for any issue type,  "bug" for example, Project settings >> Email requests:
   1. 
3. Now, create an issue from the customer portal for the bug request type.
4. Wait for the 'Issue created' notification. The reply-to in the email is the email address configured on the Email requests, as expected.
5. Now, create an issue from the customer portal that is not a bug, a  feature request type for example.
6. Wait for the 'Issue created' notification. The reply-to in the email is the email address configured for the bug Mail Channel:

Expected Results

If a Mail Channel was not created for a particular issue type, JSM should not populate the "Reply-To" with the email address of another Mail Channel.

The reply should act as if there was no Mail Channel at all (redirect back to Jira email address).

Actual Results

If the issue type does not have a Mail Channel associated to it, JSM is using the email address from the 1st Mail Channel it finds.

Workaround

If you have any version above 5.4.19, create a Mail Channel for each issue type will be necessary.