fr: replace "silencer" with "masquer" throughout (#4197)
fr: replace "silencer" with "masquer" throughout (#4197)

* fr.json: replace "silencer" with "masquer"

"Silencer" as a verb does not exist in French. A good and valid replacement is "masquer".

* FR translation: use "masquer" for "silence"

kibousoft/mastodon,kibousoft/mastodon,kibousoft/mastodon,kibousoft/mastodon