Remove redundant imports from the augmentation_gallery (#5900)

Signed-off-by: Janusz Lisiecki <[email protected]>

Author: JanuszL

docs/examples/image_processing/augmentation_gallery.ipynb

@@ -20,9 +20,6 @@
     "from nvidia.dali import pipeline_def\n",
     "import nvidia.dali.fn as fn\n",
     "import nvidia.dali.types as types\n",
-    "import numpy as np\n",
-    "from timeit import default_timer as timer\n",
-    "import numpy as np\n",
     "import matplotlib.pyplot as plt\n",
     "import math\n",
     "import os.path\n",