Check for 'rst2man' misses installed 'rst2man.py' (#4728)
By default, 'docutils' installs 'rst2man' as 'rst2man.py'. Amend the check for 'rst2man' to look for 'rst2man.py' as well if 'rst2man' is not found.
By default, 'docutils' installs 'rst2man' as 'rst2man.py'. Amend the check for 'rst2man' to look for 'rst2man.py' as well if 'rst2man' is not found.