Updated openstack/openstack
Project: openstack/horizon  c7f9b35710ada9fd8291da2bdd806ecf3b2c2fdd

Update customizing docs, css was replaced by .less

Docs still refer to style.css, but we're using horizon.less
for ages now. The docs should reflect that. The size of the logo
changed as well.

Change-Id: Ib4fc0624cc71e226895c7cef1567948d7f82d277