Fix problematic body tag attributes after upgrading to TYPO3 9 LTS

[josefglatz]

https://forge.typo3.org/issues/86979

A pending patch (UPSTREAM) is already on Gerrit https://review.typo3.org/#/c/58661/. The patch itself fixes my problems: the page row is available after applying the patch.

An actual workaround would be to use {page:field_name}