Fix typo

I think "overwrite" should be "override", shouldn't it? Surely command line flags don't write to the configuration files, unless I am severely misunderstanding something.

Yes, they OVERRULE them. So maybe it should be OVERRULE. Or SMASH?

"Override" is by far the most popular term, according to Google:

• https://www.google.com/search?hl=en&q=command%20line%20settings%20override%20configuration%20file
• https://www.google.com/search?hl=en&q=command+line+settings+overrule+configuration+file&nfpr=1
• https://www.google.com/search?hl=en&q=command%20line%20settings%20smash%20configuration%20file

merged