Commit 288bfb0bbd added a test that uses QLineEditIconButton, which
requires QT_BUILD_INTERNAL to be defined in order for the findChild()
call to work as expected.
Change-Id: Ieda18f4e26a91322e8a83c14f8d1fbbe4313ecf0
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>