Mark tst_qgl as insignificant in angle build

All ci nodes are currently missing 3d support, when that is enabled
this test will start to fail.

Task-number: QTQAINFRA-711
Change-Id: Ie6b840e290a9371fa895681e58d6dedf55b777e6
Reviewed-by: Gunnar Sletta <gunnar.sletta@digia.com>