Fix typo in device name
Fix typo in device name

The previous section discusses /dev/drbd0 and this section
uses /dev/drbd1. Rename the second occurence to /dev/drbd0.

Change-Id: I6d30fdcc308a6655a7ce570a68a07cfce091c71e
Closes-Bug: #1276423

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