Print version requires config file

[gw0]

One would expect to be able to print the version of pnapctl without any config file.

Steps to reproduce:

$ ls -al ~/.pnap
ls: cannot access '/root/.pnap': No such file or directory
$ pnapctl version
A config file is required to run this program.
There are 3 approaches to specify the path of a configuration file (in order of priority)
...