Update error message (#4417)

### What problem does this PR solve?

1. Update error message
2. Remove space characters

### Type of change

- [x] Refactoring

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

docs/guides/start_chat.md

 :::tip NOTE
 
 Click the light bubble icon above the answer to view the expanded system prompt:
-   
+
 ![](https://github.com/user-attachments/assets/515ab187-94e8-412a-82f2-aba52cd79e09)
-   
+
 Scroll down the expanded prompt to view the time consumed for each task:
-   
+
 ![enlighten](https://github.com/user-attachments/assets/fedfa2ee-21a7-451b-be66-20125619923c)
 :::
 

rag/utils/es_conn.py

                 logger.warning(f"{str(e)}. Waiting Elasticsearch {settings.ES['hosts']} to be healthy.")
                 time.sleep(5)
         if not self.es.ping():
-            msg = f"Elasticsearch {settings.ES['hosts']} didn't become healthy in 120s."
+            msg = f"Elasticsearch {settings.ES['hosts']} is unhealthy in 120s."
             logger.error(msg)
             raise Exception(msg)
         v = self.info.get("version", {"number": "8.11.3"})

rag/utils/infinity_conn.py

                 logger.warning(f"{str(e)}. Waiting Infinity {infinity_uri} to be healthy.")
                 time.sleep(5)
         if self.connPool is None:
-            msg = f"Infinity {infinity_uri} didn't become healthy in 120s."
+            msg = f"Infinity {infinity_uri} is unhealthy in 120s."
             logger.error(msg)
             raise Exception(msg)
         logger.info(f"Infinity {infinity_uri} is healthy.")