sysutils/bareos-client: Fix packaging with PYTHON=ON for Python 3.8+
- Since Python 3.8.7 (and also 3.9.2), .so files get an extension, e.g. ".cpython-38.so" if built with Python 3.8.
- Also fix testport stage QA pkg-plist issues and omit PORTREVISION bump as the content of the package doesn't change.
PR: 252568
Reported by: Brad Ackerman <brad@facefault.org>
Approved by: acm (maintainer)