fix httpclientstreamablehttptransport handleConnectionClosed log

Author: taobaorun

mcp-core/src/main/java/io/modelcontextprotocol/client/transport/HttpClientStreamableHttpTransport.java

@@ -252,7 +252,6 @@ private void handleException(Throwable t) {
 	}
 
 	private void handleConnectionClosed() {
-		logger.debug("Handling connection closed for session {}", sessionIdOrPlaceholder(this.activeSession.get()));
 		Consumer<Void> handler = this.connectionClosedHandler.get();
 		if (handler != null) {
 			handler.accept(null);

mcp-core/src/test/java/io/modelcontextprotocol/client/transport/HttpClientStreamableHttpTransportConnectionClosedHandlingTest.java

@@ -101,6 +101,7 @@ void stopServer() {
 	void testTransportConnectionClosedHandler() throws URISyntaxException {
 		AtomicReference<Boolean> closedHandlerCalled = new AtomicReference<>(false);
 		var transport = HttpClientStreamableHttpTransport.builder(HOST)
+			.openConnectionOnStartup(true)
 			.connectionClosedHandler(v -> closedHandlerCalled.set(true))
 			.build();