Fix a typo in the summary quantum operations tutorial notebook (#1015)

Author: alexini-mv

tutorials/circuits/3_summary_of_quantum_operations.ipynb

@@ -1002,7 +1002,7 @@
     "\\begin{pmatrix}\n",
     "1 & 0\\\\\n",
     "0 & e^{-i \\pi/4}\n",
-    "\\end{pmatrix}= u1(-pi/4)\n",
+    "\\end{pmatrix}= u1(-\\pi/4)\n",
     "$$"
    ]
   },
@@ -3162,7 +3162,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.7.7"
+   "version": "3.8.2"
   },
   "varInspector": {
    "cols": {