ENG-12976.  Better SSL usability in for python client (#4781)
ENG-12976.  Better SSL usability in for python client (#4781)

* ENG-12976.  Better SSL usability in for python client
  - Allow ssl_config_file to have environment variables or ~
  - Better error message when pyjks module is missing


VoltDB/voltdb,deerwalk/voltdb,deerwalk/voltdb,VoltDB/voltdb,simonzhangsm/voltdb,VoltDB/voltdb,VoltDB/voltdb,deerwalk/voltdb,VoltDB/voltdb,deerwalk/voltdb,simonzhangsm/voltdb,simonzhangsm/voltdb,simonzhangsm/voltdb,simonzhangsm/voltdb,deerwalk/voltdb,simonzhangsm/voltdb,simonzhangsm/voltdb,deerwalk/voltdb,deerwalk/voltdb,VoltDB/voltdb,simonzhangsm/voltdb,deerwalk/voltdb,VoltDB/voltdb