Update StackAnalyzerView.java

Author: KwonMunsoo

scouter.client/src/scouter/client/stack/views/StackAnalyzerView.java

@@ -99,6 +99,10 @@ public void widgetDefaultSelected(SelectionEvent event) {
 			}
 			public void widgetSelected(SelectionEvent event) {
 				TreeItem item = (TreeItem)event.item;
+				
+				if(item == null)
+					return;
+					
                 Object object = item.getData();
                 MainProcessor mainProcessor = MainProcessor.instance();
                 if ( object instanceof StackAnalyzedInfo ) {