test: Remove check for QT_{BEGIN,END}_HEADER in tst_Headers
test: Remove check for QT_{BEGIN,END}_HEADER in tst_Headers

The QT_{BEGIN,END}_HEADER macro has not ever worked and
it might be potentially removed.

Task-number: QTQAINFRA-324
Change-Id: I18ba151a0d3f92d6bdc3125b54f1a8cdd1799a69
Reviewed-by: Thiago Macieira <0ed1648d92ca0373297a182b1dba1b974ad10d88@intel.com>
Reviewed-by: Simo Fält <b598cfbc9cb80e3067479e5abd365cdf44c9b327@digia.com>
Reviewed-by: Janne Anttila <237e68234a327a5775cffcea05af0474ad4190b9@digia.com>

tsarajar/qtqa,tsarajar/qtqa,tsarajar/qtqa,tsarajar/qtqa