fix: update MILVUS_URI in .env.example for correct service endpoint

Author: hhhhsc701

runtime/deer-flow/.env.example

@@ -55,7 +55,7 @@ TAVILY_API_KEY=tvly-xxx
 
 # RAG_PROVIDER: milvus  (using free milvus instance on zilliz cloud: https://docs.zilliz.com/docs/quick-start )
 RAG_PROVIDER=milvus
-MILVUS_URI=http://milvus-standalone:19530
+MILVUS_URI=http://milvus:19530
 MILVUS_USER=root
 MILVUS_PASSWORD=Milvus
 MILVUS_AUTO_LOAD_EXAMPLES=false