Minor fixes to Sahara UI Installation Guide
Minor fixes to Sahara UI Installation Guide

 * removed item #7 - it is not needed and is misleading
 * rephrased clarification for AUTO_ASSIGNMENT_ENABLED
 * renamed 'Nova Network' to 'Nova-Network' - seems like the later is
   the only name which is used

Partial-Implements: blueprint update-docs-icehouse
Change-Id: Ibb177820da8d44e1f70a8fd7273dadd57e81ad1e

esikachev/scenario,keedio/sahara,xme1226/sahara,crobby/sahara,redhat-openstack/sahara,esikachev/sahara-backup,ekasitk/sahara,zhangjunli177/sahara,tellesnobrega/sahara,crobby/sahara,matips/iosr-2015,redhat-openstack/sahara,citrix-openstack-build/sahara,esikachev/scenario,citrix-openstack-build/sahara,mapr/sahara,citrix-openstack-build/sahara,keedio/sahara,ekasitk/sahara,esikachev/sahara-backup,crobby/sahara,henaras/sahara,bigfootproject/sahara,openstack/sahara,henaras/sahara,zhujzhuo/Sahara,tellesnobrega/sahara,zhujzhuo/Sahara,openstack/sahara,zhangjunli177/sahara,henaras/sahara,matips/iosr-2015,egafford/sahara,tellesnobrega/storm_plugin,ekasitk/sahara,keedio/sahara,bigfootproject/sahara,tellesnobrega/storm_plugin,zhujzhuo/Sahara,redhat-openstack/sahara,egafford/sahara,esikachev/sahara-backup,zhangjunli177/sahara,xme1226/sahara,matips/iosr-2015,mapr/sahara,xme1226/sahara,bigfootproject/sahara,esikachev/scenario,mapr/sahara,tellesnobrega/storm_plugin