Don't fatal in ElasticSearch setup check if no "master" database is configured

Summary:
Ref T12965. See that task for discussion, and PHI36 for context.

This sweeps the fatal under the rug by skipping it, letting things move forward for now.

Test Plan: Followed instructions in T12965, got a read-only recovery after restart instead of a fatal.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T12965

Differential Revision: https://secure.phabricator.com/D18440

src/applications/config/check/PhabricatorElasticsearchSetupCheck.php

@@ -7,6 +7,12 @@ final class PhabricatorElasticsearchSetupCheck extends PhabricatorSetupCheck {
   }
 
   protected function executeChecks() {
+    // TODO: Avoid fataling if we don't have a master database configured
+    // but have the MySQL search index configured. See T12965.
+    if (PhabricatorEnv::isReadOnly()) {
+      return;
+    }
+
     $services = PhabricatorSearchService::getAllServices();
 
     foreach ($services as $service) {