We need to skip the exifReadComments test case if reading text from
image has been configured off, like in webOS's Yocto recipe for QtBase.
Fixes: QTBUG-105393
Pick-to: 6.4
Change-Id: If45872ca7ed26620fa38bc6b47132363d661acdc
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>