Builds from master branch of m2crypto are broken on Windows

[HMaker]

I tried to build m2crypto from current master branch but it failed with "libssl.so not found" errors, the setup.py doesn't handle Windows environment correctly anymore (I guess it's a bug).

So the README should suggest people to target the release branches through git clone's --branch argument:

git clone --branch 0.38.0 https://gitlab.com/m2crypto/m2crypto
cd m2crypto
python -m venv venv --prompt=m2crypto
.\venv\Scripts\activate
python -m pip install wheel pywin32
python setup.py build --openssl="C:\Program Files\OpenSSL-Win64" --bundledlls
python setup.py bdist_wheel