Changes

mpc: update to 1.2.1 and add test results

 (commit: 2150000)

Add nzbget 21.1

Co-authored-by: erwinlem <erwin.github-oi@bk3.nl>
 (commit: 898f39a)

pyrsistent: Add 0.18.0 for jsonschema

 (commit: 02d48b6)

bump pkg(5) dependencies for Python 3.9

* pycurl: build for Python 3.9

* ply: build for Python 3.9

* contextlib2: build for Python 3.9 (where it might not be necessary?)

* tempora: build for Python 3.9

* portend: build for Python 3.9

* cherrypy: build for Python 3.9

* pybonjour: build for Python 3.9

* prettytable: build for Python 3.9

* jsonschema: Bump to 3.2.0 for Python 3.9

* pycurl: bump to 7.44.1 for Python 3.9 compatibility

* jsonrpclib: bump to 0.4.3 for Python 3.9 compatibility

* mod_wsgi: bump to 4.9.0 for Python 3.9 compatibility

* cheroot: use the PollSelector (which fixes missed wakeups)

Co-authored-by: Andy Fiddaman <omnios@citrus-it.co.uk>
 (commit: 10fc8cc)

jsonschema: add runtime dependency on pyrsistent

 (commit: c62d352)

jsonschema: fix runtime dependency on pyrsistent

 (commit: 9c0007e)

jsonschema: add more runtime dependencies

 (commit: b9a73af)