fix ValueError for click>=8.0
Since click version 8.0, the following error occurs:
Traceback (most recent call last):
File "/home/lukas/.local/bin/pandoc-acronyms", line 5, in <module>
from filter.pandocacronyms import filter
File "/home/lukas/.local/lib/python3.9/site-packages/filter/pandocacronyms.py", line 18, in <module>
def filter(acronyms, verbose, suggest, error, debug, format):
File "/home/lukas/.local/lib/python3.9/site-packages/click/decorators.py", line 247, in decorator
_param_memo(f, OptionClass(param_decls, **option_attrs))
File "/home/lukas/.local/lib/python3.9/site-packages/click/core.py", line 2465, in __init__
super().__init__(param_decls, type=type, multiple=multiple, **attrs)
File "/home/lukas/.local/lib/python3.9/site-packages/click/core.py", line 2099, in __init__
raise ValueError(
ValueError: 'default' must be a list when 'multiple' is true.
This uses [''] instead of '' as default parameter and fixes that issue