Fix netapp_enable_multiattach default for E-Series
Fix netapp_enable_multiattach default for E-Series

The E-Series driver erroneously changed the netapp_enable_multiattach
option to default to True. This option should default to False to
ensure backwards-compatibility with upgrades.

DocImpact
Closes-Bug: #1491580
Change-Id: Iafb4d80bd83c2de0a5b77178206c7f3028ac6554

apporc/cinder,ge0rgi/cinder,mahak/cinder,openstack/cinder,NetApp/cinder,Datera/cinder,phenoxim/cinder,NetApp/cinder,eharney/cinder,eharney/cinder,openstack/cinder,phenoxim/cinder,apporc/cinder,Datera/cinder,cloudbase/cinder,bswartz/cinder,j-griffith/cinder,scality/cinder,cloudbase/cinder,scality/cinder,bswartz/cinder,j-griffith/cinder,Hybrid-Cloud/cinder,dims/cinder,Paul-Ezell/cinder-1,Hybrid-Cloud/cinder,dims/cinder,Nexenta/cinder,mahak/cinder,Nexenta/cinder,Paul-Ezell/cinder-1