I could be wrong but I believe that it is either a recut or repunched Date depending upon whether the Dates were cut into the Die along with the other details and lettering or if they manually punched the Dates. I know little of the French Mints and do not know whether they were still using manual Minting Presses or had gone to hydraulic (steam powered) Minting Presses but don't believe that it is Machine Doubling. See examples at the links below.