Pcbnew: fix incorrect rotation angle unit when building thermal spokes

The new Rotate function uses radians, not deci-degrees.

Fixes #3668 | https://gitlab.com/kicad/code/kicad/issues/3668

pcbnew/zone_filler.cpp

@@ -980,7 +980,7 @@ void ZONE_FILLER::buildThermalSpokes( const ZONE_CONTAINER* aZone,
                     break;
                 }
 
-                spoke.Rotate( padAngle );
+                spoke.Rotate( -DECIDEG2RAD( padAngle ) );
                 spoke.Move( shapePos );
 
                 spoke.SetClosed( true );