cleanup security-guide ch025_web-dashboard
cleanup security-guide ch025_web-dashboard

made change to Horizon dashboard description in beginning of xml file
removing extra white space

Change-Id: I8a776010c06e0af99b2317475823355a3c6a4f18

AlekhyaMallina-Vedams/openstack-manuals,potsmaster/openstack-manuals,Akasurde/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,gongysh2004/openstack-manual,potsmaster/openstack-manuals,saeki-masaki/openstack-manuals,Akasurde/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,gongysh2004/openstack-manual,saeki-masaki/openstack-manuals,kairoaraujo/openstack-manuals,kairoaraujo/openstack-manuals