Docs: correct expected host format for drac_address
Docs: correct expected host format for drac_address

The iDRAC driver expects a hostname or IP address in the drac_address
field of the driver_info. Passing a URL does not work.

Change-Id: I999f84ef5d7bc4b10cb8cf8dabdeb1f17172e824

openstack/ironic,openstack/ironic