[1.6.x] Fixed #22116 -- Added precision about WSGIPythonPath separator

If you install your project's Python dependencies inside a `virtualenv`_,

you'll need to add the path to this virtualenv's ``site-packages`` directory to

your Python path as well. To do this, add an additional path to your

`WSGIPythonPath` directive, with multiple paths separated by a colon::

``WSGIPythonPath`` directive, with multiple paths separated by a colon (``:``)

if using a UNIX-like system, or a semicolon (``;``) if using Windows. If any

part of a directory path contains a space character, the complete argument

string to ``WSGIPythonPath`` must be quoted::

    WSGIPythonPath /path/to/mysite.com:/path/to/your/venv/lib/python2.X/site-packages