[BUGFIX] PHP 5.4 E_STRICT warning in HtmlViewHelper

Creating the TSFE instance in HtmlViewHelper raises a PHP 5.4
warning 'Creating default Object from empty value'.

Change-Id: Ie269945e4257306cd9a80b2829795c6b1c3e0969
Releases: 6.1, 6.0, 4.7, 4.5
Resolves: #46393
Reviewed-on: https://review.typo3.org/18996
Reviewed-by: Alexander Schnitzler
Tested-by: Alexander Schnitzler
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn