Check if Salesforce contact exists (missing Contact on dev) (#1248)

Co-authored-by: Michael Volo <volo@rice.edu>

Author: Dantemss

app/routines/update_salesforce_assignable_fields.rb

@@ -17,6 +17,8 @@ def call(created_after)
       next if contact_id.nil?
 
       contact = OpenStax::Salesforce::Remote::Contact.find(contact_id)
+      next if contact.nil?
+
       contact.assignable_interest = 'Fully Integrated'
       contact.assignable_adoption_date = external_id.min_created_at
       contact.save!