Speed up the graceful shutdown test slightly.

This one has been spuriously failing me for a while.  I'd like it to
consistently run, but I'll settle for 3x more likely for now.

src/test/java/net/spy/memcached/ProtocolBaseCase.java

@@ -433,7 +433,7 @@ public void testGracefulShutdownTooSlow() throws Exception {
 			client.set("t" + i, 10, i);
 		}
 		assertFalse("Weird, shut down too fast",
-			client.shutdown(3, TimeUnit.MILLISECONDS));
+			client.shutdown(1, TimeUnit.MILLISECONDS));
 
 		try {
 			Map<SocketAddress, String> m = client.getVersions();