Log error rather than using sysout

Author: ctrueden

src/main/java/org/scijava/ui/swing/script/FileSystemTree.java

@@ -181,7 +181,7 @@ public synchronized Node getChildAt(final int index) {
 			try {
 				return (Node) super.getChildAt(index);
 			} catch (ArrayIndexOutOfBoundsException ae) {
-				System.out.println("FileSystemTree: no child at index " + index + " for file at " + this.path);
+				log.error("FileSystemTree: no child at index " + index + " for file at " + this.path, ae);
 				return null;
 			}
 		}