climex.ipynb: fix Jenkins failure due to climex link on wrong server

Should have used the climex link on PAVICS prod server instead of the
test server.

`TEST_USE_PROD_DATA` should be on the same line as "pavics.ouranos.ca" to
avoid it being replaced by the test server during Jenkins run.

The precommit autoformatter should not break that line.

See previous fix that was lost
75652fb

docs/source/notebooks/climex.ipynb

@@ -112,9 +112,11 @@
     "from IPython.display import HTML, Markdown\n",
     "from xclim import ensembles as xens\n",
     "\n",
-    "cat = intake.open_esm_datastore(\n",
-    "    \"https://pavics.ouranos.ca/catalog/climex.json\"\n",
-    ")  # TEST_USE_PROD_DATA\n",
+    "# fmt: off\n",
+    "climex = \"https://pavics.ouranos.ca/catalog/climex.json\"  # TEST_USE_PROD_DATA\n",
+    "cat = intake.open_esm_datastore(climex)\n",
+    "# fmt: on\n",
+    "\n",
     "cat.df.head()"
    ]
   },