[BUGFIX] Fix wrong type hint for emitAfterExtensionT3DImportSignal()

Fix a wrong type hint for the second parameter in
InstallUtility::emitAfterExtensionT3DImportSignal(). The parameter is of
type integer and not array.

Resolves: #60179
Releases: 6.3, 6.2
Change-Id: Iccfb7445bd374edaecfd3408380034dbec82e539
Reviewed-on: https://review.typo3.org/31503
Reviewed-by: Wouter Wolters
Reviewed-by: Oliver Hader
Tested-by: Oliver Hader