show diff on history tab opens two browser tabs with diff page
Cloned from https://bugzilla.redhat.com/show_bug.cgi?id=1254909
Description of problem:
When you click on show diff on the history page of a provisioning template (which has a history), it opens duplicate tabs in the browser.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Create custom prov template and submit
2. Change template and submit
3. Click on show diff on the history tab of template
Tested with Firefox 39.0.3 on Fedora and Firefox 40 on Windows.