[Nightly] Optimize nightly online test logger info (#4798)

### What this PR does / why we need it?
This patch do some tiny optimization for nightly ci:

1. Polling the frequency with which the service prints logs when it
starts up in order to obtain useful information more quickly.
2. Shorten the timeout for waiting server

- vLLM version: v0.12.0
- vLLM main:
ad32e3e19c

---------

Signed-off-by: wangli <wangli858794774@gmail.com>

tests/e2e/nightly/multi_node/test_multi_node.py

@@ -114,7 +114,7 @@ async def test_multi_node() -> None:
                 proxy_port=proxy_port,
                 disaggregated_prefill=disaggregated_prefill,
                 nodes_info=nodes_info,
-                max_wait_seconds=2000,
+                max_wait_seconds=1200,
         ) as remote_server:
             if config.is_master:
                 port = proxy_port if disaggregated_prefill else server_port