traceback rendering ctld when FC is used

[2020/07/22 13:13:37] (ERROR) EtcService.generate():238 - Failed to render py:ctld
Traceback (most recent call last):
File "/usr/local/lib/python3.7/site-packages/middlewared/plugins/etc.py", line 236, in generate
rendered = await renderer.render(path)
File "/usr/local/lib/python3.7/site-packages/middlewared/plugins/etc.py", line 56, in render
mod.render, self.service, self.service.middleware,
File "/usr/local/lib/python3.7/site-packages/middlewared/utils/run_in_thread.py", line 10, in run_in_thread
return await self.loop.run_in_executor(self.run_in_thread_executor, functools.partial(method, *args, **kwargs))
File "/usr/local/lib/python3.7/site-packages/middlewared/utils/io_thread_pool_executor.py", line 25, in run
result = self.fn(*self.args, **self.kwargs)
File "/usr/local/lib/python3.7/site-packages/middlewared/etc_files/ctld.py", line 425, in render
main(middleware)
File "/usr/local/lib/python3.7/site-packages/middlewared/etc_files/ctld.py", line 376, in main
if not t2e.iscsi_extent.iscsi_target_extent_enabled:
AttributeError: 'NoneType' object has no attribute 'iscsi_target_extent_enabled'