Update sample to use OpenID Connect and Provider Configuration endpoint

Issue gh-53 gh-55

samples/boot/oauth2-integration/client/src/main/java/sample/config/SecurityConfig.java

@@ -40,10 +40,10 @@ public class SecurityConfig {
 	SecurityFilterChain securityFilterChain(HttpSecurity http) throws Exception {
 		http
 			.authorizeRequests(authorizeRequests ->
-				authorizeRequests.anyRequest().permitAll()
+				authorizeRequests.anyRequest().authenticated()
 			)
-			.logout()
-				.disable()
+			.oauth2Login(oauth2Login ->
+				oauth2Login.loginPage("/oauth2/authorization/messaging-client-oidc"))
 			.oauth2Client(withDefaults());
 		return http.build();
 	}