Switch default security filter back on

If the user sets security.basic.enabled=false he has to remember
to @EnableWebSecurity.  Possibly we could be more helpful about the
exception, but I think this might be pilot error.

Fixes gh-568

spring-boot-samples/spring-boot-sample-web-secure/src/main/java/sample/ui/secure/SampleSecureApplication.java

@@ -52,8 +52,7 @@ public class SampleSecureApplication extends WebMvcConfigurerAdapter {
 
 	public static void main(String[] args) throws Exception {
 		// Set user password to "password" for demo purposes only
-		new SpringApplicationBuilder(SampleSecureApplication.class).properties(
-				"security.basic.enabled=false", "security.user.password=password").run(
+		new SpringApplicationBuilder(SampleSecureApplication.class).properties("security.user.password=password").run(
 				args);
 	}