Add a config option for json_script instead of unconditionally including
all json files in /etc/uhttpd in every uhttpd instance. This makes it
possible to configure a single instance with an unconditional redirect,
which currently renders all other uhttpd instances unusable.
Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>
Acked-by: Felix Fietkau <nbd@nbd.name>