fixed corrupted job file recovery

jess/jobs.py

@@ -294,7 +294,7 @@ class Tracker(object):
             jess_log.debug('         loading job file {}'.format(self._job_file))
             try:
                 job = Job.load(self._job_file)
-            except EOFError:
+            except (EOFError, ValueError) as e:
                 # job file probably corrupted; remove it and re-submit new job
                 os.remove(self._job_file)
                 job = self._jmi.submit()