Fix chapter number

ritiek · web-flow · commit 1dc2c48d217f · 2017-10-30T00:46:08.000+05:30
diff --git a/ch02_basics/Concept09_queue.ipynb b/ch02_basics/Concept09_queue.ipynb
@@ -4,7 +4,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "# Ch `01`: Concept `09`"
+    "# Ch `02`: Concept `09`"
    ]
   },
   {
