Fix Elasticsearch template condition if no client is defined

This commit makes sure to backoff if a Client bean is not available.

Closes gh-10143

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/elasticsearch/ElasticsearchDataAutoConfigurationTests.java

@@ -46,6 +46,14 @@ public class ElasticsearchDataAutoConfigurationTests {
 		}
 	}
 
+	@Test
+	public void templateBackOffWithNoClient() {
+		this.context = new AnnotationConfigApplicationContext(
+				ElasticsearchDataAutoConfiguration.class);
+		assertThat(this.context.getBeanNamesForType(ElasticsearchTemplate.class))
+				.isEmpty();
+	}
+
 	@Test
 	public void templateExists() {
 		load("spring.data.elasticsearch.properties.path.data:target/data",