remove the new flag just added

theano/configdefaults.py

@@ -538,13 +538,6 @@ AddConfigVar(
     BoolParam(True, allow_override=True),
     in_c_key=False)
 
-AddConfigVar(
-    'list_rejected_optimizers',
-    "List all optimizers rejected during optimization",
-    BoolParam(True, allow_override=True),
-    in_c_key=False)
-
-
 """Note to developers:
     Generally your exceptions should use an apply node's __str__
     method when exception_verbosity == 'low'. When exception_verbosity