packaging: setup: correctly parse stroage domain info

previously the getStorageDomainInfo parser assumed that
remotePath was always defined in the dictionary returned
by the call to getStorageDomainInfo.
The key is not defined for iSCSI domains so now the
parser check for remotePath availability before
trying to use its value.

Change-Id: I7e8db0f31dadd7072680fb1564514be065ea5431
Bug-Url: https://bugzilla.redhat.com/1005767
Signed-off-by: Sandro Bonazzola <sbonazzo@redhat.com>