Add ability to edit the prefix for subtasks when being cloned.

Users in many situations do not want to have the prefix "CLONE - " in subtask's summary when they clone a ticket with its subtasks. Currently, the prefix are added to the subtasks' summary several times if a ticket with its subtasks is cloned several times. (Please see the attached screenshot to illustrate this issue)

• Steps to reproduce this problem.

1. create a ticket, and let's say its key is [TEST-1]
2. create 3 subtasks within [TEST-1] ticket; [TEST-2], [TEST-3], [TEST-4]
3. clone [TEST-1] with its subtasks, and let's say this main ticket is called [TEST-5] with its subtasks ([TEST-6], [TEST-7], [TEST-8]).
4. clone [TEST-5] with its subtasks, and let's say this main ticket is called [TEST-9] with its subtasks ([TEST-10], [TEST-11], [TEST-12]).
5. clone [TEST-9] with its subtasks, and let's say this main ticket is called [TEST-13] with its subtasks ([TEST-14], [TEST-15], [TEST-16]).
6. by this time, the summary of the subtasks of [TEST-14], [TEST-15], [TEST-16] will have a summary called "CLONE - CLONE - CLONE - blah..blah..blah.."

BTW, I can't clone the ticket [TEST-1] to have the ticket [TEST-13] because there are changes in the tickets [TEST-5] and [TEST-9].
Also, I can't remove prefix from jira-application.properties file because users still want to see the prefix "CLONE -" for main tickets, not subtasks.

Although Atlassian fixed JRA-15164, they broke other people's purpose(JSP-81226, JRA-23868). Ideally, jira-application.properties should contain two separate properties to add the prefix for cloning issues: one is for main ticket and the other is for subtasks. In this way, both users' requests can be fulfilled. Could you add this feature in near future JIRA version?

Thanks