Ensure we load credentials *before* passenger forks

Change-Id: Iebcfefb753746d526093e46e59c34a43095b9b96
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/276531
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Ethan Vizitei <evizitei@instructure.com>
QA-Review: Jacob Burroughs <jburroughs@instructure.com>
Product-Review: Jacob Burroughs <jburroughs@instructure.com>

config/application.rb

@@ -344,6 +344,8 @@ module CanvasRails
 
     initializer "canvas.init_credentials", before: "active_record.initialize_database" do
       self.credentials = Canvas::Credentials.new(credentials)
+      # Ensure we load credentials at initailization time to avoid overloading vault
+      self.credentials.config
     end
 
     # we don't know what middleware to make SessionsTimeout follow until after