devel/py-virtualenvwrapper: Fix virtualenvwrapper_lazy.sh wrapper

Fix the virtualenvwrapper_lazy.sh wrapper to invoke the Python
versions-specific virtualenvwrapper.sh script that the port/package was
built with, preventing the following error:

ERROR: virtualenvwrapper_lazy.sh: Could not find virtualenvwrapper.sh

While I'm here:

• Update pkg-descr WWW: URL to match setup.py:homepage
• Update COMMENT to match setup.py:summary

Approved by: portmgr (blanket: ports (python) compliance, run-time bugfix)
MFH: 2020Q1 (blanket: ports (python) compliance, run-time bugfix)