[BUGFIX] Import Fluid namespace in Step layout of install tool

Namespace “i” is used but never imported. This patch fixes that.

Change-Id: Iba5a5e97cb633298b9993fca5c5b5f655f36feaf
Resolves: #81765
Releases: master, 8.7
Reviewed-on: https://review.typo3.org/53375


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Joerg Boesche <typo3@joergboesche.de>
Tested-by: Joerg Boesche <typo3@joergboesche.de>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>