[Health-dev] Improve SYSINFO command

[Gerald Wiese]

Hi,

I was investigating how to properly set the desired environment 
variables GNUHEALTH_VERSION & TRYTON_VERSION for the SYSINFO command.

My problem was that I wanted to read them dynamically from pip version 
but I could not manage to make uWSGI or systemd to do so on environment 
variables.

And I would prefer to avoid passing .gnuhealthrc or a shell script to 
the service.

However I ended up finding a way to eliminate them. The following change 
on health.py enables to read those versions using the importlib library 
instead:

22d21
< import importlib.metadata
5675c5674
< f"{importlib.metadata.version('gnuhealth')}\n"
---
> f"{os.environ['GNUHEALTH_VERSION']}\n"
5677c5676
<         tryton_version = f"Tryton server: 
{importlib.metadata.version('trytond')}\n"
---
>         tryton_version = f"Tryton server: 
{os.environ['TRYTON_VERSION']}\n"

Was introduced in Python 3.8 which is the oldest Python version that did 
not reach end of life:

https://docs.python.org/3/library/importlib.metadata.html

Not sure what that would mean for openSUSE.

What do you think?

Best

Gerald