Fix pipeline reference

Author: photonstorm

src/gameobjects/graphics/GraphicsWebGLRenderer.js

@@ -47,12 +47,12 @@ var GraphicsWebGLRenderer = function (renderer, src, interpolationPercentage, ca
         return;
     }
 
-    var pipeline = this.pipeline;
+    var pipeline = renderer.currentPipeline;
 
     var camMatrix = pipeline._tempMatrix1;
     var graphicsMatrix = pipeline._tempMatrix2;
     var currentMatrix = pipeline._tempMatrix4;
-   
+
     renderer.setPipeline(pipeline);
 
     currentMatrix.loadIdentity();