Set Search API Unicorn timeout to 15s
Set Search API Unicorn timeout to 15s

This matches the search-api nginx config. See 7e06998abfe25ed26329db3ad5ef6b9863a02301
for motivation.

https://trello.com/c/CVrZaaPv/1320

alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet