Fix typo

This was preventing shadow maps properties from being updated correctly. What happened was:
- onChange would trigger for WebGLShadowMap model
- The base class syncToModel was called due to the typo
- `save_changes` was called, which clears the `changed` attributes etc.
- The `change` listener on `Renderer` would trigger, and try to look at the changed attributes.

There might be a benefit to wrapping that save_changes call in a "callSoon" function?

Author: vidartf

js/src/renderers/webgl/WebGLShadowMap.js

@@ -24,7 +24,7 @@ class WebGLShadowMapModel extends WebGLShadowMapAutogenModel {
         // Leave this to Renderable
     }
 
-    synToModel(syncAllProps) {
+    syncToModel(syncAllProps) {
         // Leave this to Renderable
     }