If the package does not have a tanker, the refueling task will cause AI
flights to go to an arbitrary tanker, which may cause them to fly
through enemy territory or even go farther than their arrival airbase.
It's also not remotely possible for every AI flight in the game to
refuel in most missions. There's typically one tanker and dozens of
aircraft that would previously attempt to refuel.
Fixes https://github.com/dcs-liberation/dcs_liberation/issues/2716.
a6c5b03212