Improve Point Defence reaction

[walder]

This part of the code should check if pd is in range of shooting down the HARM:

currently it activates the PD 20 NM out, this is a bit far out.

could check max shooting distance + 15% for example.

if ( #self:getPointDefences() > 0 and self:pointDefencesGoLive() == true and self.iads:getDebugSettings().harmDefence ) then
     self.iads:printOutputToLog("POINT DEFENCES GOING LIVE FOR: "..self:getDCSName().." | TTI: "..secondsToImpact)
end