Fixed initialization issues with dynamic lights.

Actors get initialized from their defaults so anything done in the constructor or some explicit member initialization will be overwritten.
They must use their properties for setting up configurable fields and do the rest in BeginPlay.

src/g_shared/a_dynlight.cpp

@@ -167,6 +167,7 @@ void ADynamicLight::BeginPlay()
 
 	specialf1 = DAngle(double(SpawnAngle)).Normalized360().Degrees;
 	visibletoplayer = true;
+	mShadowmapIndex = 1024;
 }
 
 //==========================================================================