change validation before casting

Author: bernardodemarco

server/src/main/java/org/apache/cloudstack/backup/BackupManagerImpl.java

@@ -62,7 +62,6 @@
 import org.apache.cloudstack.backup.dao.BackupScheduleDao;
 import org.apache.cloudstack.context.CallContext;
 import org.apache.cloudstack.framework.config.ConfigKey;
-import org.apache.cloudstack.framework.jobs.AsyncJob;
 import org.apache.cloudstack.framework.jobs.AsyncJobDispatcher;
 import org.apache.cloudstack.framework.jobs.AsyncJobManager;
 import org.apache.cloudstack.framework.jobs.impl.AsyncJobVO;
@@ -674,7 +673,7 @@ protected void sendExceededBackupLimitAlert(String ownerUuid, Resource.ResourceT
      * @return The backup schedule ID. Returns null if the backup has been manually created
      */
     protected Long getBackupScheduleId(Object job) {
-        if (!(job instanceof AsyncJob)) {
+        if (!(job instanceof AsyncJobVO)) {
             return null;
         }