Remove debug output that can cause crashes in static builds.

Currently static builds ignore the accessibility plugins.
The debug output would also potentially crash for
other events when they could not create interfaces.

Task-number: QTBUG-28707
Change-Id: I5ae20cac89bd7f4a74add2b80834f4e9d4fa438c
Reviewed-by: Jan Arve Sæther <jan-arve.saether@digia.com>
Remove extra $ in default libexec directory

Produces qt_lbexpath=$PREFIX/29677QT_INSTALL_LIBEXECS_DIRNAME
in qconfig.cpp

Change-Id: Ie6f208d759a748dfcd4f1547943a1dfb4b7aedd5
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Kai Koehne <kai.koehne@digia.com>