[FIX] doc: remove outdated warning

In 13.0, we use the IoTBox which handle https correctly
12.0 was still a transition version but people should have switched in
13.0

closes odoo/odoo#39845

X-original-commit: 5d44adcd
Signed-off-by: Martin Trigaux (mat) <mat@odoo.com>

doc/setup/deploy.rst

@@ -273,12 +273,6 @@ just about any SSL termination proxy, but requires the following setup:
 * Your SSL termination proxy should also automatically redirect non-secure
   connections to the secure port
 
-.. warning::
-
-  In case you are using the Point of Sale module in combination with a `POSBox`_,
-  you must disable the HTTPS configuration for the route ``/pos/web`` to avoid
-  mixed-content errors.
-
 Configuration sample
 --------------------