docs: updated wrong output in Upstash Redis Cache section of LLM Ca… (#15140)

…ching documentation

<!-- Thank you for contributing to LangChain!

Please title your PR "<package>: <description>", where <package> is
whichever of langchain, community, core, experimental, etc. is being
modified.

Replace this entire comment with:
  - **Description:** a description of the change, 
  - **Issue:** the issue # it fixes if applicable,
  - **Dependencies:** any dependencies required for this change,
- **Twitter handle:** we announce bigger features on Twitter. If your PR
gets announced, and you'd like a mention, we'll gladly shout you out!

Please make sure your PR is passing linting and testing before
submitting. Run `make format`, `make lint` and `make test` from the root
of the package you've modified to check this locally.

See contribution guidelines for more information on how to write/run
tests, lint, etc: https://python.langchain.com/docs/contributing/

If you're adding a new integration, please include:
1. a test for the integration, preferably unit tests that do not rely on
network access,
2. an example notebook showing its use. It lives in
`docs/docs/integrations` directory.

If no one reviews your PR within a few days, please @-mention one of
@baskaryan, @eyurtsev, @hwchase17.
 -->


- **Description:** Fixed the wrong output and code block comment in
`Upstash Redis` Cache section of LLM Caching documentation,
  - **Issue:** #15139 ,
  - **Dependencies:** N/A,
- **Twitter handle:** [@vardhaman722](https://twitter.com/vardhaman722)

docs/docs/integrations/llms/llm_caching.ipynb

@@ -287,7 +287,7 @@
     {
      "data": {
       "text/plain": [
-       "'\\n\\nTwo guys stole a calendar. They got six months each.'"
+       "'\\n\\nWhy did the chicken cross the road?\\n\\nTo get to the other side!'"
       ]
      },
      "execution_count": 50,
@@ -297,7 +297,7 @@
    ],
    "source": [
     "%%time\n",
-    "# The first time, it is not yet in cache, so it should take longer\n",
+    "# The second time it is, so it goes faster\n",
     "llm(\"Tell me a joke\")"
    ]
   },