_registerself fails when readdoc doc_id not found

[damies13]

See log:

Exception in thread Thread-2 (_servedb):
Traceback (most recent call last):
  File "/usr/lib/python3.10/threading.py", line 1016, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.10/threading.py", line 953, in run
    self._target(*self._args, **self._kwargs)
  File "/home/dave/.local/lib/python3.10/site-packages/MyNoSQL/__init__.py", line 285, in _servedb
    self.doc_id = self._registerself()
  File "/home/dave/.local/lib/python3.10/site-packages/MyNoSQL/__init__.py", line 595, in _registerself
    doc = self.readdoc(self.doc_id)
  File "/home/dave/.local/lib/python3.10/site-packages/MyNoSQL/__init__.py", line 960, in readdoc
    raise Exception("doc", doc_id, "not found")
Exception: ('doc', '3236b84e-7ecd-11ed-9557-ab88946e4365', 'not found')