rake task gitlab:env:info doesn't show Elasticsearch

Summary

We've started using elasticsearch, and we've noticed that the rake task gitlab:env:info doesn't show Elasticsearch as enabled. gitlab:check and the admin panel do show it correctly as enabled.

Steps to reproduce

$ bundle exec rake gitlab:check RAILS_ENV=production && bundle exec rake gitlab:env:info RAILS_ENV=production

Expected behavior

Elasticsearch version >= 2.0? ... yes (2.4.1)  
Elasticsearch has plugin delete-by-query installed? ... yes  
  
Checking GitLab ... Finished  

GitLab information
Version:        8.13.1-ee
...
Elasticsearch:  yes

Actual behavior

Elasticsearch version >= 2.0? ... yes (2.4.1)  
Elasticsearch has plugin delete-by-query installed? ... yes  
  
Checking GitLab ... Finished  

GitLab information
Version:        8.13.1-ee
...
Elasticsearch:  no

Otherwise everything, including the elasticsearch integration, seems to work fine, so it seems to just be a minor bug in one of the rake tasks.