Just released version 8.5 which added one important feature: compatibility with recent versions of JIRA for authentication. It’s now using basic authentication (no more username/passwords in the URL in clear…). Of course you should still make sure to use HTTPS and not HTTP.
This releases also changes the minimum version of XWiki required to use it; you’ll now need XWiki 8.4+.
See http://extensions.xwiki.org/xwiki/bin/view/Extension/JIRA%20Macro#Hv8.5
Enjoy
PS: Special thanks to Christopher Spears for his PR