chore: update default plunker link

Author: kara

.github/ISSUE_TEMPLATE.md

@@ -10,7 +10,7 @@
 #### What are the steps to reproduce?
 
 Providing a Plunker (or similar) is the *best* way to get the team to see your issue.
-Plunker template: http://plnkr.co/edit/o077B6uEiiIgkC0S06dd
+Plunker template: https://goo.gl/DlHd6U
 
 
 #### What is the use-case or motivation for changing an existing behavior?