check the lapis code error instead of text message

(1) If I18n.locale is not English, then this error message will be
localized, so won't match this condition (for example, for Portuguese
it will be "Este item já existe").

(2) The copy for the error message may change in the future.

app/graph/mutations/graphql_crud_operations.rb

@@ -11,7 +11,7 @@ def self.safe_save(obj, attrs, parent_names = [])
     begin
       obj.save_with_version!
     rescue RuntimeError => e
-      if e.message.include?("This item already exists") &&
+      if e.message.include?("\"code\":9") &&
       obj.is_a?(ProjectMedia) &&
       obj.set_fact_check.present? &&
       obj.set_original_claim.present?