The caption "Le Pape a Paris: Les Français aussi cons que les nègres" from Charlie Hebdo's cover of issue n°498 (24 mai 1980),

allegedly translates as follows:
The Pope in Paris: The French are as stupid as n*gg*rs.
The English edition of Wiktionary describes “nègre” as equivalent to “negro”, rather than the n word, and doesn't warn about it as being offensive.
How racist is the word? Is it really on par with the n word in English?