Polish Documentation

docs/guides/src/asciidoc/_hello-includes/secure-the-application.asc

@@ -51,12 +51,11 @@ The next step is to create a Spring Security configuration.
 package org.springframework.security.samples.config;
 
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.context.annotation.Configuration;
 import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
 import org.springframework.security.config.annotation.web.configuration.*;
 
 @EnableWebSecurity
-public class SecurityConfig extends WebSecurityConfigurerAdapter {
+public class SecurityConfig {
 
     @Autowired
     public void configureGlobal(AuthenticationManagerBuilder auth) throws Exception {