Fix typos in sys-git/install-client-proxy.sls and sys-usb/install-client-proxy.sls

[wassp-ds]

Commitment

I confirm that I have read the following resources:

• How to ask questions The Smart Way
• Writing the perfect question
• Question checklist
• Could you please make my preference the default?

@ben-grande as a "thank you" note, see title of this bug :)

In both cases: mab-db -> man-db.

[ben-grande]

Thanks.