Update StringToDurationConverter link in LoadBalancerCacheProperties (#1729)

Signed-off-by: Tran Ngoc Nhan <ngocnhan.tran1996@gmail.com>

Author: ngocnhan-tran1996

docs/modules/ROOT/partials/_configprops.adoc

@@ -43,7 +43,7 @@
 |spring.cloud.loadbalancer.cache.caffeine.spec |  | The spec to use to create caches. See CaffeineSpec for more details on the spec format.
 |spring.cloud.loadbalancer.cache.capacity | `+++256+++` | Initial cache capacity expressed as int.
 |spring.cloud.loadbalancer.cache.enabled | `+++true+++` | Enables Spring Cloud LoadBalancer caching mechanism.
-|spring.cloud.loadbalancer.cache.ttl | `+++35s+++` | Time To Live - time counted from writing of the record, after which cache entries are expired, expressed as a {@link Duration}. The property {@link String} has to be in keeping with the appropriate syntax as specified in Spring Boot <code>StringToDurationConverter</code>. @see <a href= "https://github.com/spring-projects/spring-boot/blob/master/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/convert/StringToDurationConverter.java">StringToDurationConverter.java</a>
+|spring.cloud.loadbalancer.cache.ttl | `+++35s+++` | Time To Live - time counted from writing of the record, after which cache entries are expired, expressed as a {@link Duration}. The property {@link String} has to be in keeping with the appropriate syntax as specified in Spring Boot <code>StringToDurationConverter</code>. @see <a href= "https://github.com/spring-projects/spring-boot/blob/main/core/spring-boot/src/main/java/org/springframework/boot/convert/StringToDurationConverter.java">StringToDurationConverter.java</a>
 |spring.cloud.loadbalancer.call-get-with-request-on-delegates | `+++true+++` | If this flag is set to {@code true}, {@code ServiceInstanceListSupplier#get(Request request)} method will be implemented to call {@code delegate.get(request)} in classes assignable from {@code DelegatingServiceInstanceListSupplier} that don't already implement that method, with the exclusion of {@code CachingServiceInstanceListSupplier} and {@code HealthCheckServiceInstanceListSupplier}, which should be placed in the instance supplier hierarchy directly after the supplier performing instance retrieval over the network, before any request-based filtering is done, {@code true} by default.
 |spring.cloud.loadbalancer.clients |  | 
 |spring.cloud.loadbalancer.configurations | `+++default+++` | Enables a predefined LoadBalancer configuration.

spring-cloud-loadbalancer/src/main/java/org/springframework/cloud/loadbalancer/cache/LoadBalancerCacheProperties.java

@@ -37,7 +37,7 @@ public class LoadBalancerCacheProperties {
 	 * in keeping with the appropriate syntax as specified in Spring Boot
 	 * <code>StringToDurationConverter</code>.
 	 * @see <a href=
-	 * "https://github.com/spring-projects/spring-boot/blob/master/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/convert/StringToDurationConverter.java">StringToDurationConverter.java</a>
+	 * "https://github.com/spring-projects/spring-boot/blob/main/core/spring-boot/src/main/java/org/springframework/boot/convert/StringToDurationConverter.java">StringToDurationConverter.java</a>
 	 */
 	private Duration ttl = Duration.ofSeconds(35);