Issue Summary

Sprints created in Jira are not syncing to JA unless an Issue/Story is pulled into a new empty Jira Board Sprint. This is occurring due JA is creating duplicated entries on the Sprint Mapping.

Steps to Reproduce

1. To replicate this (option "Map Sprints based on Their End Date" is being used)
2. Create a PI with anchor Sprints in JA 
3. Create some Sprints on Jira that matches the anchor, and wait for them to sync to JA
4. On JA > Jira Management > Jira Sprints, select one of the Sprints and click on "Ignore Sprints From Mapping"
5. Run a SyncBoard and see how it will create a duplicate of the Sprint in question
6. Create more Sprints on Jira, without Stories on it
7. On JA run a new BoardSync and notice how these Sprints will not sync to JA anymore

Expected Results

After a boar sync, the sprints are created in JA regardless they have issues associated with it or not. 

Actual Results

Sprints created in Jira are not syncing to JA unless an Issue/Story is pulled into a new empty Jira Board Sprint.

Workaround

Add at least 1 issues e.g. a story to the sprint and it will sync with JA as expected.