separator not valid in Field creation

[bcrickboom]

Hi, It seems that there is a bug introduced in 0.4.3 version. Indeed, with 0.4.2 version, I can write that:

import hl7
f=hl7.Field("|", ["MSH"])
print(f)
MSH

With version 0.4.3 (and later):

import hl7
f=hl7.Field("|", ["MSH"])
Traceback (most recent call last):
  File "/snap/pycharm-community/312/plugins/python-ce/helpers/pydev/pydevconsole.py", line 364, in runcode
    coro = func()
  File "<input>", line 1, in <module>
  File "/home/bc/Orthanc-Team/python-orthanc-tools/venv3/lib/python3.8/site-packages/hl7/containers.py", line 784, in __init__
    assert not separator or separator == separators[2]
AssertionError

Is it the expected behavior ?

Thanks for your support and your great job!