[DLMED] fix cron test error (Project-MONAI#417)

Signed-off-by: Nic Ma <nma@nvidia.com>

Author: Nic-Ma

3d_segmentation/unet_segmentation_3d_ignite.ipynb

@@ -486,22 +486,6 @@
     "![image-2.png](attachment:image-2.png) ![image-4.png](attachment:image-4.png)"
    ]
   },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Visualizing training status in MLFlow"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "%mlflow ui"
-   ]
-  },
   {
    "attachments": {
     "image.png": {
@@ -511,6 +495,10 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
+    "## Visualizing training status in MLFlow\n",
+    "\n",
+    "As `mlflow` is not IPython component, please switch to the `log_dir` and execute command `mlflow ui` to launch MLFlow UI.\n",
+    "\n",
     "Expected training curve on MLFlow UI:\n",
     "![image.png](attachment:image.png)"
    ]