Fix the error in log_in_dashboard.rst
Fix the error in log_in_dashboard.rst

The images tab is not sub tab of volumes tab.
The 'System Info' should be 'System Information'.

Change-Id: Idff8d4c90b3db36c9c8b97ce71b4e87523412f27

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