Delete link which is not exist. (Azure#18945)

Author: Rujun Chen

sdk/spring/azure-spring-cloud-autoconfigure/README.md

@@ -32,7 +32,6 @@ Note that there is no need to add a `version` as those are managed already by th
 ## Key concepts
 This project provides auto-configuration for the following Azure services:
 
-- [Azure App Configuration][app_configuration]
 - [Azure Cache][cache]
 - [Event Hubs][event_hubs]
 - [Event Hubs Kafka][event_hubs_kafka]
@@ -44,8 +43,6 @@ This project provides auto-configuration for the following Azure services:
 
 The following section provides sample projects illustrating how to use the Azure Spring Cloud starters.
 ### More sample code
-- [Azure App Configuration][app_configuration_sample]
-- [Azure App Configuration Conversation][app_configuration_conversation_sample]
 - [Azure Cache][cache_sample]
 - [Event Hubs][event_hubs_sample]
 - [Event Hubs Kafka][event_hubs_kafka_sample]
@@ -74,8 +71,6 @@ For more information about setting logging in spring, please refer to the [offic
 
 The following section provides sample projects illustrating how to use the Azure Spring Cloud starters.
 ### More sample code
-- [Azure App Configuration][app_configuration_sample]
-- [Azure App Configuration Conversation][app_configuration_conversation_sample]
 - [Azure Cache][cache_sample]
 - [Event Hubs][event_hubs_sample]
 - [Event Hubs Kafka][event_hubs_kafka_sample]
@@ -98,15 +93,12 @@ Please follow [instructions here][contributing_md] to build from source or contr
 [logging_doc]: https://docs.spring.io/spring-boot/docs/current/reference/html/spring-boot-features.html#boot-features-logging
 [contributing_md]: https://github.com/Azure/azure-sdk-for-java/tree/master/sdk/spring/CONTRIBUTING.md
 [maven]: https://maven.apache.org/
-[app_configuration]: https://github.com/Azure/azure-sdk-for-java/tree/master/sdk/appconfiguration/azure-spring-cloud-starter-appconfiguration-config
 [cache]: https://github.com/Azure/azure-sdk-for-java/tree/master/sdk/spring/azure-spring-cloud-starter-cache
 [event_hubs]: https://github.com/Azure/azure-sdk-for-java/tree/master/sdk/spring/azure-spring-cloud-starter-eventhubs
 [event_hubs_kafka]: https://github.com/Azure/azure-sdk-for-java/tree/master/sdk/spring/azure-spring-cloud-starter-eventhubs-kafka
 [service_bus]: https://github.com/Azure/azure-sdk-for-java/tree/master/sdk/spring/azure-spring-cloud-starter-servicebus
 [storage]: https://github.com/Azure/azure-sdk-for-java/tree/master/sdk/spring/azure-spring-starter-storage
 [storage_queue]: https://github.com/Azure/azure-sdk-for-java/tree/master/sdk/spring/azure-spring-cloud-starter-storage-queue
-[app_configuration_sample]: https://github.com/Azure/azure-sdk-for-java/tree/master/sdk/spring/azure-spring-boot-samples/azure-spring-cloud-sample-appconfiguration
-[app_configuration_conversation_sample]: https://github.com/Azure/azure-sdk-for-java/tree/master/sdk/spring/azure-spring-boot-samples/azure-spring-cloud-sample-appconfiguration-conversion-complete
 [cache_sample]: https://github.com/Azure/azure-sdk-for-java/tree/master/sdk/spring/azure-spring-boot-samples/azure-spring-cloud-sample-cache
 [event_hubs_sample]: https://github.com/Azure/azure-sdk-for-java/tree/master/sdk/spring/azure-spring-boot-samples/azure-spring-integration-sample-eventhubs
 [event_hubs_kafka_sample]: https://github.com/Azure/azure-sdk-for-java/tree/master/sdk/spring/azure-spring-boot-samples/azure-spring-cloud-sample-eventhubs-kafka