Use throw type routes instead of copying routes into table 220 for passthrough policies
Linux has a special route type "throw", which makes the routing engine pretend no matching route was found in the table.
That could be more useful in adding routes for passthrough policies than what strongSwan does right now (basically copying the routes from the main table into table 220).
Merge branch 'throw-type-routes'
Implements simpler routes for passthrough policies on Linux, which
basically act as fallbacks on routes in other routing tables. This way
they require less information (e.g. no interface or source IP) and can
be installed earlier and are not affected by updates.