Fixed error reported in log file.

invalid style for listing block: code

src/docs/asciidoc/jme3/intermediate/appsettings.adoc

@@ -58,6 +58,7 @@ public void toggleToFullscreen() {
 [TIP]
 ====
 To view your current settings, use the System class.
+
 [code, java]
 ----
 AppSettings settings = new AppSettings(true);