Revert "- PKG-INFO metadata generation seems to be broken (lists main…

…tainer as author on PyPI - mutually exclusive?)"

More than a year after the original commit this has been fixed in
setuptools[1] so we can go back to the way it was intended to be.

This reverts commit 34ff560.

[1] pypa/setuptools#1294

setup.py

@@ -155,8 +155,10 @@ def main():
         sys.stdout.write("To install, run 'python setup.py install'\n\n")
 
     setup_options = dict(
-        author='David P. D. Moss, Stefan Nordhausen et al',
+        author='David P. D. Moss et al',
         author_email='drkjam@gmail.com',
+        maintainer='Stefan Nordhausen',
+        maintainer_email='stefan.nordhausen@immobilienscout24.de',
         classifiers=classifiers,
         description='A network address manipulation library for Python',
         download_url='https://pypi.org/project/netaddr/',