docs: Fix example in Custom DSLs for http.csrf()

It should use lambda dsl to compile

Signed-off-by: Guillaume Husta <guillaume.husta@gmail.com>

docs/modules/ROOT/pages/servlet/configuration/java.adoc

@@ -496,7 +496,7 @@ public class MyCustomDsl extends AbstractHttpConfigurer<MyCustomDsl, HttpSecurit
 	public void init(HttpSecurity http) {
 		// any method that adds another configurer
 		// must be done in the init method
-		http.csrf().disable();
+		http.csrf(csrf -> csrf.disable());
 	}
 
 	@Override