Make ConduitCall always local/in-process

Summary:
Ref T2783. ConduitCall currently has logic to pick a random remote server, but this is ultimately not appropriate: we always want to send requests to a specific server. For example, we want to send repository requests to a server which has that repository locally. The repository tier is not homogenous, so we can't do this below the call level.

Make ConduitCall always-local; logic above it will select ConduitCall for an in-process request or do service selection for an off-host request via ConduitClient.

Test Plan:
  - Browsed some pages using ConduitCall, everything worked.
  - Grepped for removed stuff.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T2783

Differential Revision: https://secure.phabricator.com/D10959

src/aphront/configuration/AphrontApplicationConfiguration.php

@@ -107,7 +107,6 @@ abstract class AphrontApplicationConfiguration {
     $prod_uri     = PhabricatorEnv::getEnvConfig('phabricator.production-uri');
     $file_uri     = PhabricatorEnv::getEnvConfig(
       'security.alternate-file-domain');
-    $conduit_uris = PhabricatorEnv::getEnvConfig('conduit.servers');
     $allowed_uris = PhabricatorEnv::getEnvConfig('phabricator.allowed-uris');
 
     $uris = array_merge(
@@ -115,7 +114,6 @@ abstract class AphrontApplicationConfiguration {
         $base_uri,
         $prod_uri,
       ),
-      $conduit_uris,
       $allowed_uris);
 
     $cdn_routes = array(