in case of general exception no need to execute the rest of the method

Original commit: elastic/x-pack-elasticsearch@d0cdaf037d

elasticsearch/src/main/java/org/elasticsearch/xpack/prelert/scheduler/ScheduledJobRunner.java

@@ -97,6 +97,7 @@ public class ScheduledJobRunner extends AbstractComponent {
                 } catch (Exception e) {
                     logger.error("Failed lookback import for job [" + job.getId() + "]", e);
                     holder.stop(e);
+                    return;
                 }
                 if (next != null) {
                     doScheduleRealtime(next, job.getId(), holder);