Name of global custom attributes are not managed by the inventory (#41786)

contrib/inventory/vmware_inventory.py

@@ -397,7 +397,7 @@ class VMWareInventory(object):
             cfm = content.customFieldsManager
             if cfm is not None and cfm.field:
                 for f in cfm.field:
-                    if f.managedObjectType == vim.VirtualMachine:
+                    if not f.managedObjectType or f.managedObjectType == vim.VirtualMachine:
                         self.custom_fields[f.key] = f.name
                 self.debugl('%d custom fields collected' % len(self.custom_fields))
         except vmodl.RuntimeFault as exc: