After the recent changes, there is only one global nDPI struct which
is share across all the interfaces. However, the struct can be swapped
during normal operating, so it's necessary to reload the associations
every time a new nDPI struct is allocated.
Fixes#3139
- devices with no preset defined have a 'allow all' default policy
- users customizations to the preset are stored on redis (both 'allow' and 'drop' policies) as exceptions to the default preset
- default presets updates are allowed, however users customizations have priority (per protocol)
