Shade SAM threat ranges.

This runs a little bit worse but looks a lot better. Will flip back off
if this runs poorly on less powerful computers.

resources/ui/map/map.js

@@ -161,7 +161,6 @@ function drawSamThreatsAt(tgo) {
     L.circle(tgo.position, {
       radius: range,
       color: threatColor,
-      fill: false,
       weight: 1,
     }).addTo(threatLayer);
   });