Allow "Wait for Message" to be unset on build plans

Summary: Fixes T11910. I spent a couple of minutes looking for the root cause without much luck, but this will all be obsoleted by an eventual upgrade to `EditEngine` anyway.

Test Plan: Set and unset "Wait for Message", which now worked.

Reviewers: chad, avivey

Reviewed By: avivey

Subscribers: PHID-OPKG-gm6ozazyms6q6i22gyam

Maniphest Tasks: T11910

Differential Revision: https://secure.phabricator.com/D16919

src/applications/harbormaster/customfield/HarbormasterBuildStepCoreCustomField.php

@@ -43,7 +43,7 @@ final class HarbormasterBuildStepCoreCustomField
           'the result for this step. After the result is recorded, the build '.
           'plan will resume.'),
         'options' => array(
-          '' => pht('Continue Build Normally'),
+          'continue' => pht('Continue Build Normally'),
           'wait' => pht('Wait For Message'),
         ),
       );

src/applications/harbormaster/step/HarbormasterBuildStepImplementation.php

@@ -237,7 +237,8 @@ abstract class HarbormasterBuildStepImplementation extends Phobject {
       return false;
     }
 
-    return (bool)$target->getDetail('builtin.wait-for-message');
+    $wait = $target->getDetail('builtin.wait-for-message');
+    return ($wait == 'wait');
   }
 
   protected function shouldAbort(