Build index even for RST only change
Build index even for RST only change

Build the index.html file also when only RST files changed.

Change-Id: I50a59fad6a5ca5deda8c6aad6ad2667f9b16321a

openstack/openstack-doc-tools,savinash47/openstack-doc-tools,savinash47/openstack-doc-tools,openstack/openstack-doc-tools,savinash47/openstack-doc-tools