Remove phabricator.conduit-uri config setting

Summary:
We have phabricator.conduit-uri in the config setting, but it
is always the phabricator uir appended with '/api'. So we just remove
this setting.

Test Plan:
test arc diff to make sure it still work.

Reviewed By: epriestley
Reviewers: epriestley
CC: jungejason, epriestley
Differential Revision: 71

conf/default.conf.php

@@ -22,12 +22,6 @@ return array(
   // Example: "http://phabricator.example.com/"
   'phabricator.base-uri'        => null,
 
-  // The Conduit URI for API access to this install. Normally this is just
-  // the 'base-uri' plus "/api/" (e.g. "http://phabricator.example.com/api/"),
-  // but make sure you specify 'https' if you have HTTPS configured.
-  'phabricator.conduit-uri'     => null,
-
-
   // The default PHID for users who haven't uploaded a profile image. It should
   // be 50x50px.
   'user.default-profile-image-phid' => 'PHID-FILE-f57aaefce707fc4060ef',

src/applications/people/controller/settings/PhabricatorUserSettingsController.php

@@ -171,8 +171,6 @@ class PhabricatorUserSettingsController extends PhabricatorPeopleController {
       $notice = null;
     }
 
-    $host = PhabricatorEnv::getEnvConfig('phabricator.conduit-uri');
-
     $cert_form = new AphrontFormView();
     $cert_form
       ->setUser($user)