Permits the use of an empty reason

[loicvh]

As a way to keep the verbosity to minimum (in log and in the code), I think this would be nice to be able to left the "reason" empty (e.g., if the reason is too obvious or too long).

@deprecat(deprecated_args={'a':{'version':'4.0'}, 'b':{'version':'3.0'}})
def multiply(a, b, c):
    return 42

Currently the code above raises an error:

Traceback (most recent call last):
File "", line 1, in
File "/opt/homebrew/lib/python3.11/site-packages/deprecat/classic.py", line 205, in wrapper_function
msg = adapter.get_deprecated_msg(wrapped_, instance_, kwargs_)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/opt/homebrew/lib/python3.11/site-packages/deprecat/classic.py", line 120, in get_deprecated_msg
if self.deprecated_args[arg]['reason']:
~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^

While, IMO, it would be great to show

>>> multiply(a=1,b=2,c=3)
:1: DeprecationWarning: Call to deprecated Parameter a. -- Deprecated since v4.0.
:1: DeprecationWarning: Call to deprecated Parameter b. -- Deprecated since v3.0.
42

If needed, I'd be happy to help and implement this feature.