Apply default settings only if no json file is loaded / improve pairing speed

[switchabl]

• Only apply -a -g -H0 -A if no CLI arguments are given and no json file was loaded
• Always show the lower part of the welcome message, even when options are given (I thought this made sense; if you don't like it I will revert)
• Fixed calls to close for the json file (parentheses are required since Python 3, otherwise it does nothing)

I was investigating the pairing delay problem and in the process I realized that the default settings are applied even if a settings file is present. In particular, pedal stroke analysis is always active, even on trainers that don't support it. This appears to interfere with the pairing process (why remains to be investigated).

With the patch, pairing of the Genius or Vortex+HU for me is consistently

• immediate with ANTUSB-m
• < 5s with older ANTUSB2

[WouterJD]

-A implies multi-processing
FortiusAntBody's functions run in it's own process, the GUI in the parent process.

GUI functions (like SetValues) send a message to the GUIprocess.

Woukd this impact?

[switchabl]

@WouterJD I always thought multi-processing was on by default anyway. But I have to admit I have never really looked at that part of the code properly.

To be honest, I have no clue why -A interferes with pairing. I stumbled on this by accident because it worked with one setup and not with another, so I compared logs and I found that was the only difference. And that turning it off in the settings doesn't do anything because of the bug.

If I figure out what is actually going on I'll let you know.

Do you have any thoughts on the the PR? I assume overriding the settings like this is not expected behaviour and should be fixed in any case, right?

[WouterJD]

I will check into detail shortly and think i willmerge as suggested

[WouterJD]

Kind a busy these days

[switchabl]

No worries, I know the feeling. Take your time to check it properly. Don't want to fix one bug and make a new one.