This patch bumps web2py to the latest version R-2.15.4 and bumps
also the python-pydal dependency to the required latest version 17.8.
Starting with version R-2.15.x web2py supports also python 3, so
updating the package to support both versions.
Signed-off-by: Angelo Compagnucci <angelo.compagnucci@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>