fix: handle active storage preview error for password protected pdfs (#11888)

Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>

config/application.rb

@@ -61,6 +61,9 @@ module Chatwoot
     # https://discuss.rubyonrails.org/t/cve-2022-32224-possible-rce-escalation-bug-with-serialized-columns-in-active-record/81017
     # FIX ME : fixes breakage of installation config. we need to migrate.
     config.active_record.yaml_column_permitted_classes = [ActiveSupport::HashWithIndifferentAccess]
+
+    # Disable PDF/video preview generation as we don't use them
+    config.active_storage.previewers = []
   end
 
   def self.config