NetApp fix to set non default server port in api

The non default netapp_server_port config option was not
getting set in api even if specified in cinder.conf. Its
made non mandatory and set if specified in the configuration.

Change-Id: I62943427e0caac2742cce4ce56c1a49917f9210d
Closes-bug: #1322379
Merge "NetApp fix to set non default server port in api"