Remove link to modindex
Remove link to modindex

The documentation build does not generate any module index, thus remove
the link to the page. The page
http://docs.openstack.org/infra/storyboard/py-modindex.html
does not exist.

Change-Id: I67f82ea4fcf47ff95d3416e73380c3b58c287d2b

ColdrickSotK/storyboard,ColdrickSotK/storyboard,ColdrickSotK/storyboard