bitbake: toaster: settings set ALLOWED_HOSTS to * in debug mode

bitbake: toaster: settings set ALLOWED_HOSTS to * in debug mode

As of Django 1.8.16, Django is rejecting any HTTP_HOST header that is
not on the ALLOWED_HOST list.  We often need to reference the
toaster server via a fqdn, if we start it via webport=0.0.0.0:8000 for
instance, and are hitting the server from a laptop. This change does
reduce  the protection from a DNS rebinding attack, however, if you are
running the toaster server outside a protected network, you should be
using the production instance.

[YOCTO #10578]

(Bitbake rev: 59a3f391ac5ac194f30d11a39676356464269d55)

Signed-off-by: brian avery <brian.avery@intel.com>
Signed-off-by: Michael Wood <michael.g.wood@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>