[MXAPPS-581] Disable an additional long test in the SD nightly (apach…

…e#12343)

* Disable an additional test in the SD nightly that also takes over the
  timeout.

tests/nightly/straight_dope/test_notebooks_single_gpu.py

@@ -41,6 +41,7 @@
     'chapter07_distributed-learning/multiple-gpus-scratch',
     'chapter07_distributed-learning/multiple-gpus-gluon',
     'chapter07_distributed-learning/training-with-multiple-machines',
+    'chapter08_computer-vision/visual-question-answer', # > 10 mins.
     'chapter11_recommender-systems/intro-recommender-systems',  # Early draft, non-working.
     'chapter12_time-series/intro-forecasting-gluon',
     'chapter12_time-series/intro-forecasting-2-gluon',
@@ -226,9 +227,6 @@ def test_object_detection(self):
     def test_fine_tuning(self):
         assert _test_notebook('chapter08_computer-vision/fine-tuning')
 
-    def test_visual_question_answer(self):
-        assert _test_notebook('chapter08_computer-vision/visual-question-answer')
-
     # Chapter 9
 
     def test_tree_lstm(self):