Default to "True" and "False" for bool options.

Summary:
Rather than throwing if we don't `setOptions()`, let's just default to `true`
and `false`.

Test Plan:
Removed a `setOptions()` call temporarily and saw options default to
`true` / `false`.

Reviewers: epriestley, btrahan, chad

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T2255

Differential Revision: https://secure.phabricator.com/D4368

src/applications/config/controller/PhabricatorConfigEditController.php

@@ -350,8 +350,8 @@ final class PhabricatorConfigEditController
           ->setOptions(
             array(
               ''      => pht('(Use Default)'),
-              'true'  => idx($option->getOptions(), 0),
-              'false' => idx($option->getOptions(), 1),
+              'true'  => idx($option->getBoolOptions(), 0),
+              'false' => idx($option->getBoolOptions(), 1),
             ));
         break;
       case 'class':