Deprecate spring.cloud.vault.aws.use-nonce.

The property use-nonce was not used and makes no sense hence deprecating this property.

See gh-103.

docs/src/main/asciidoc/spring-cloud-vault.adoc

@@ -241,17 +241,6 @@ further investigation.
 
 The nonce is kept in memory and is lost during application restart.
 
-.bootstrap.yml with disabled nonce
-====
-[source,yaml]
-----
-spring.cloud.vault:
-    authentication: AWS_EC2
-    aws-ec2:
-        use-nonce: false
-----
-====
-
 AWS-EC2 authentication roles are optional and default to the AMI.
 You can configure the authentication role by setting the
 `spring.cloud.vault.aws-ec2.role` property.
@@ -277,7 +266,6 @@ spring.cloud.vault:
         role: application-server
         aws-ec2-path: aws-ec2
         identity-document: http://...
-        use-nonce: false
 ----
 ====
 
@@ -286,7 +274,6 @@ authentication method
 * `role` sets the role name of the AWS EC2 role definition
 * `aws-ec2-path` sets the path of the AWS EC2 mount to use
 * `identity-document` sets URL of the PKCS#7 AWS EC2 identity document
-* `use-nonce` setting this value to `false` will disable nonce usage
 
 See also: https://www.vaultproject.io/docs/auth/aws-ec2.html[Vault Documentation: Using the aws-ec2 auth backend]
 

spring-cloud-vault-config/src/main/java/org/springframework/cloud/vault/config/VaultProperties.java

@@ -13,15 +13,16 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-
 package org.springframework.cloud.vault.config;
 
 import lombok.Data;
+import lombok.Getter;
 import org.hibernate.validator.constraints.NotEmpty;
 import org.hibernate.validator.constraints.Range;
 
 import org.springframework.boot.bind.RelaxedPropertyResolver;
 import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.boot.context.properties.DeprecatedConfigurationProperty;
 import org.springframework.context.EnvironmentAware;
 import org.springframework.core.env.Environment;
 import org.springframework.core.io.Resource;
@@ -184,7 +185,11 @@ public class VaultProperties implements EnvironmentAware {
 
 		/**
 		 * Flag whether to generate and send a nonce.
+		 *
+		 * @deprecated not used, will be removed in a future version.
 		 */
+		@Getter(onMethod = @__(@DeprecatedConfigurationProperty(reason = "not used")))
+		@Deprecated
 		private boolean useNonce = true;
 	}