Fixed pass name in the sky plane technique.

Bin/CoreData/Techniques/DiffSkyplane.xml

@@ -1,3 +1,3 @@
 <technique>
-    <pass name="prealpha" vs="Unlit" ps="Unlit_Diff" depthwrite="false" />
+    <pass name="postopaque" vs="Unlit" ps="Unlit_Diff" depthwrite="false" />
 </technique>