Unneeded test case in test_streams.py

[podsvirov]

python-jsonrpc-server/test/test_streams.py

Line 84 in 73ab099

if os.name == 'nt':

The python-jsonrpc-server package now available via MSYS2 distro.

While creating this package, I noticed behavior that does not require any special handling in our case.

See 002-python-jsonrpc-server-0.4.0-fix-test.patch for more info.

I have a desire to add a python-language-server package, but there are even more failed checks.