uhttpd: don't redirect to HTTPS by default

uhttpd: don't redirect to HTTPS by default

So we can ship px5g-wolfssl by default in the release image, but still
make the HTTPS for LuCI optional. This small change with addition of
`CONFIG_PACKAGE_px5g-wolfssl=y` into the buildbot's seed config for the
next release should provide optional HTTPS in the next release.

Disabling the current default automatic uhttpd's redirect to HTTPS
should make the HTTPS optional. That's it, user would either need to
switch to HTTPS by manually switching to https:// protocol in the URL or
by issuing the following commands to make the HTTPS automatic redirect
permanent:

 $ uci set uhttpd.main.redirect_https=1
 $ uci commit uhttpd
 $ service uhttpd reload

Signed-off-by: Petr Štetiar <ynezz@true.cz>