JIRA Sprint links is using Application URL instead of Display URL

Steps to reproduce :
Pre-requisite
Create application link before proceeding with the steps below

1. Login to JIRA
2. Create an Agile Scrum project
3. Create an issue in the newly create project
4. Create a Sprint
5. Drag the newly created issue to the new Sprint

1. Now login to Confluence
2. Create a new Calendar
3. Create a "JIRA Issue Dates"
4. Select the newly created project that was created in JIRA
5. Ensure that Sprints checkbox is checked then click OK to finish the event creation process like the screenshot below
   
6. Click on the Sprint that is showing on the Team Calendar and hover over to "View Sprint" like the screenshot below :
   
   Note that it is pointing to the URL with 8080 port which is the Application URL. When it should be pointing to the Display URL as configured below :
   

Expected behavior : It should point to the display URL

Current behavior : it is pointing towards the Application URL which is wrong.

Below is the application used and it's version to replicate this issue :
JIRA 6.1.7
Confluence 5.6.5
Team Calendar 5.1.21