Revert lighting changes for 10856 causing knock-on.

indra/llinventory/llsettingssky.cpp

@@ -1684,3 +1684,4 @@ LLUUID LLSettingsSky::getNextBloomTextureId() const
 {
     return mNextBloomTextureId;
 }
+

indra/newview/app_settings/shaders/class1/windlight/atmosphericsFuncs.glsl

@@ -137,7 +137,7 @@ void calcAtmosphericVars(vec3 inPositionEye, float ambFactor, out vec3 sunlit, o
           + tmpAmbient));
 
     //brightness of surface both sunlight and ambient
-    sunlit = sunlight.rgb;
-    amblit = tmpAmbient.rgb;
+    sunlit = sunlight.rgb * 0.5;
+    amblit = tmpAmbient.rgb * .25;
     additive *= vec3(1.0 - temp1);
 }

indra/newview/app_settings/shaders/class3/lighting/lightV.glsl

@@ -32,7 +32,7 @@ vec4 sumLights(vec3 pos, vec3 norm, vec4 color);
 vec4 calcLighting(vec3 pos, vec3 norm, vec4 color)
 {
 	vec4 c = sumLights(pos, norm, color);
-    c.rgb += atmosAmbient() * color.rgb * 0.25;
+    c.rgb += atmosAmbient() * color.rgb;
     return c; 
 }