Remove text from markdown cell in Portmantout.ipynb

Removed a line from a markdown cell in the notebook.

ipynb/Portmantout.ipynb

@@ -537,7 +537,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "Just a few seconds run time; great!  "
+    "  "
    ]
   },
   {