Fix incorrect cast in NettyRoutingFilter

spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/filter/NettyRoutingFilter.java

@@ -280,7 +280,7 @@ public class NettyRoutingFilter implements GlobalFilter, Ordered {
 	static Long getLong(Object responseTimeoutAttr) {
 		Long responseTimeout = null;
 		if (responseTimeoutAttr instanceof Number) {
-			responseTimeout = ((Integer) responseTimeoutAttr).longValue();
+			responseTimeout = ((Number) responseTimeoutAttr).longValue();
 		}
 		else if (responseTimeoutAttr != null) {
 			responseTimeout = Long.parseLong(responseTimeoutAttr.toString());

spring-cloud-gateway-server/src/test/java/org/springframework/cloud/gateway/filter/NettyRoutingFilterCompatibleTests.java

@@ -56,6 +56,7 @@ class NettyRoutingFilterCompatibleTests extends BaseWebClientTests {
 	void getLongHandlesStringAndNumber() {
 		assertThat(NettyRoutingFilter.getLong("5")).isEqualTo(5);
 		assertThat(NettyRoutingFilter.getLong(5)).isEqualTo(5);
+		assertThat(NettyRoutingFilter.getLong(50000L)).isEqualTo(50000);
 		assertThat(NettyRoutingFilter.getLong(null)).isNull();
 		assertThatThrownBy(() -> NettyRoutingFilter.getLong("notanumber")).isInstanceOf(NumberFormatException.class);
 	}