checkstyle fixes and gitignore update

Author: walpurr

app/.gitignore

@@ -1,3 +1,8 @@
+*.class
+jte-classes
+*.settings
+bin
+
 **/.idea/
 /demo.cast
 **/logs/

app/src/main/java/hexlet/code/App.java

@@ -83,7 +83,7 @@ private static Javalin getApp() throws SQLException, IOException {
 
         app.get(NamedRoutes.rootPath(), ctx -> {
             String currentUser = Objects.requireNonNullElse(
-                ctx.sessionAttribute("currentUser"),"Гость"
+                ctx.sessionAttribute("currentUser"), "Гость"
             );
             var page = MainPage.of(currentUser);
             ctx.render("index.jte", model("page", page));