fix empty table - Fixes #3285097 update hook to support units on width/height

        // Restore the data.

        foreach ($tables as $table) {

          if (

            !isset($existing_data[$table])

            || !is_array($existing_data[$table])

            || !count($existing_data[$table])

          ) {

            continue;

          }

          $last_row = end($existing_data[$table]);

          if ($last_row == false) {

            continue;

          }

          $fields = array_keys($last_row);

          $insert_query = $database

            ->insert($table)

            ->fields(array_keys(end($existing_data[$table])));

            ->fields($fields);

          foreach ($existing_data[$table] as $row) {

            $insert_query->values(array_values($row));

          }