Fix typo in job.adoc

Cherry-picked from b06f90a

Issue #4591

spring-batch-docs/src/main/asciidoc/job.adoc

@@ -449,6 +449,7 @@ public class MyJobConfiguration {
 		return new JdbcTransactionManager(dataSource);
 	}
 
+	@Bean
 	public Job job(JobRepository jobRepository) {
 		return new JobBuilder("myJob", jobRepository)
 				//define job flow as needed