Fix KeyError for iSCSI parameters (#67463)

The required parameters for the LUN mapping for destination LUN is
address, port and iqn. However if the user doesn't pass parameters
like  CHAP authentication parameters, we will get KeyError. The patch
fixes the same.

lib/ansible/modules/cloud/ovirt/ovirt_vm.py

@@ -2207,13 +2207,13 @@ def _get_lun_mappings(module):
                             ['iscsi', 'fcp']) else None,
                         logical_units=[
                             otypes.LogicalUnit(
-                                id=lunMapping['dest_logical_unit_id'],
-                                port=lunMapping['dest_logical_unit_port'],
-                                portal=lunMapping['dest_logical_unit_portal'],
-                                address=lunMapping['dest_logical_unit_address'],
-                                target=lunMapping['dest_logical_unit_target'],
-                                password=lunMapping['dest_logical_unit_password'],
-                                username=lunMapping['dest_logical_unit_username'],
+                                id=lunMapping.get('dest_logical_unit_id'),
+                                port=lunMapping.get('dest_logical_unit_port'),
+                                portal=lunMapping.get('dest_logical_unit_portal'),
+                                address=lunMapping.get('dest_logical_unit_address'),
+                                target=lunMapping.get('dest_logical_unit_target'),
+                                password=lunMapping.get('dest_logical_unit_password'),
+                                username=lunMapping.get('dest_logical_unit_username'),
                             )
                         ],
                     ),