Fix typo in ElasticSearch sample notebook (#3171)

Added missing parenthesis in example notebook
[elasticsearch.ipynb](https://github.com/hwchase17/langchain/blob/master/docs/modules/indexes/vectorstores/examples/elasticsearch.ipynb)

docs/modules/indexes/vectorstores/examples/elasticsearch.ipynb

@@ -46,7 +46,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "db = ElasticVectorSearch.from_documents(docs, embeddings, elasticsearch_url=\"http://localhost:9200\"\n",
+    "db = ElasticVectorSearch.from_documents(docs, embeddings, elasticsearch_url=\"http://localhost:9200\")\n",
     "\n",
     "query = \"What did the president say about Ketanji Brown Jackson\"\n",
     "docs = db.similarity_search(query)"