json::dynamic: fix warning
json::dynamic: fix warning

Signed-off-by: Alexis Laferrière <b039e421609d7f6745b4f3c2461976cf9144304c@xymus.net>

privat/nit,privat/nit,privat/nit,privat/nit,privat/nit,privat/nit,privat/nit,privat/nit,privat/nit,privat/nit