DEV: correct regression and correct tests

etag change in 31976ecf was incorrect, revert it

Also correct regression in test suite.

lib/s3_inventory.rb

@@ -59,7 +59,6 @@ class S3Inventory
               SET etag = #{table_name}.etag
               FROM #{table_name}
               WHERE #{model.table_name}.etag IS NULL AND
-                #{model.table_name}.etag <> #{table_name}.etag AND
                 #{model.table_name}.url = #{table_name}.url")
 
             list_missing_post_uploads if type == "original"