athena.py: improve help message for --tracelevel

Control/AthenaCommon/python/AthOptionsParser.py

@@ -222,8 +222,8 @@ def getArgumentParser(legacy_args=False, **kwargs):
                             'endrun', 'stop', 'full', 'full-athena', 'all'],
                    help='perform double delete checking, disables the use of tcmalloc.')
 
-    g.add_argument('--tracelevel', metavar='LEVEL', nargs='?', type=int, choices=range(0,4), const=3,
-                   help='trace level for python configuration')
+    g.add_argument('--tracelevel', metavar='LEVEL', nargs='?', type=int, choices=range(1,4), const=3,
+                   help='trace level for python configuration (%(choices)s)')
 
     # --------------------------------------------------------------------------
     if legacy_args: