database.yml in send_grid_mailer-2.0.0

- old
+ new

@@ -1,13 +1,13 @@
-# SQLite version 3.x
+# SQLite. Versions 3.8.0 and up are supported.
 #   gem install sqlite3
 #
 #   Ensure the SQLite 3 gem is defined in your Gemfile
 #   gem 'sqlite3'
 #
 default: &default
   adapter: sqlite3
-  pool: 5
+  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
   timeout: 5000
 
 development:
   <<: *default
   database: db/development.sqlite3