Fixing typo in twistd options

Author: deniszh

lib/carbon/conf.py

@@ -506,11 +506,11 @@ def get_default_parser(usage="%prog [options] <start|stop|status>"):
         help="Manage a specific carbon instance")
     parser.add_option(
         "--logfile",
-        default='None',
+        default=None,
         help="Log to a specified file, - for stdout")
     parser.add_option(
         "--logger",
-        default='None',
+        default=None,
         help="A fully-qualified name to a log observer factory to use for the initial log "
              "observer. Takes precedence over --logfile and --syslog (when available).")
     return parser