Fixes Warning: 'firstinits' option is deprecated, use 'giveninits' instead

rapport_francais/preambule_biblatex.tex

@@ -2,7 +2,8 @@
 \usepackage[
 	backend=bibtex, 
 	style=authoryear,
-	firstinits=true,
+	uniquename=init,
+	giveninits=true,
 	natbib=true
 ]{biblatex}
 \addbibresource{biblio.bib}