Add @Configuration on @Enable*-annotated classes

servlet/spring-boot/java/oauth2/resource-server/hello-security/src/main/java/example/OAuth2ResourceServerSecurityConfiguration.java

@@ -17,6 +17,7 @@ package example;
 
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
 import org.springframework.http.HttpMethod;
 import org.springframework.security.config.annotation.web.builders.HttpSecurity;
 import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
@@ -30,6 +31,7 @@ import org.springframework.security.web.SecurityFilterChain;
  *
  * @author Josh Cummings
  */
+@Configuration
 @EnableWebSecurity
 public class OAuth2ResourceServerSecurityConfiguration {