The info bar message that shows up for web fonts is only shown once per Dreamweaver session.
You can choose to click on the cross mark next to that message to remove info bar, but it will re-appear next time when DW is quit and launched.
Reason being - There are multiple messages that are shown to users in this info bar, which aids them to perform the correct and desired results.
The ability to permanently disable info bar is currently not available. You can choose to submit a feature request for this through: