fix: Make "promruval version" not require -config-file.

[rudo-thomas]

As of 2.7.0:

$ promruval version
promruval: error: required flag --config-file not provided, try --help

This fixes it.

[rudo-thomas]

Tested locally.

The slight difference is in the output of --help -- now that the flag is not required, it is not featured on the first line. I think it's acceptable.

Merging.