IE7/IE8 javascript error when calling String.trim()

Cause: IE7 and IE8 do not have String.prototype.trim function.

Solution:
In metatag.vertical-tabs.js:

        vals.push(Drupal.t('@label: @value', {
          '@label': label.trim(),
          '@value': Drupal.truncate($(this).val(), 25) || Drupal.t('None')
        }));

Should be:

        vals.push(Drupal.t('@label: @value', {
          '@label': $.trim(label),
          '@value': Drupal.truncate($(this).val(), 25) || Drupal.t('None')
        }));