fixed inverted red and blue channels in OffScenePanel and ScenePreviewProcessor , has the default format of readFrameBuffer has been set to RGBA in jme core

jme3-core/src/com/jme3/gde/core/scene/OffScenePanel.java

@@ -219,7 +219,7 @@ public class OffScenePanel extends javax.swing.JPanel implements SceneProcessor
 
     public void postFrame(FrameBuffer fb) {
 //        cpuBuf.clear();
-        SceneApplication.getApplication().getRenderer().readFrameBuffer(offBuffer, cpuBuf);
+        SceneApplication.getApplication().getRenderer().readFrameBufferWithFormat(offBuffer, cpuBuf,Format.BGRA8);
 //
 //        // copy native memory to java memory
 //        cpuBuf.clear();

jme3-core/src/com/jme3/gde/core/scene/ScenePreviewProcessor.java

@@ -169,7 +169,7 @@ public class ScenePreviewProcessor implements SceneProcessor {
     public void postFrame(FrameBuffer fb) {
         if (currentPreviewRequest != null) {
             cpuBuf.clear();
-            SceneApplication.getApplication().getRenderer().readFrameBuffer(offBuffer, cpuBuf);
+            SceneApplication.getApplication().getRenderer().readFrameBufferWithFormat(offBuffer, cpuBuf, Format.BGRA8);
 
             // copy native memory to java memory
             cpuBuf.clear();