fix typo

Signed-off-by: raccoonback <kosb15@naver.com>

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

@@ -116,7 +116,7 @@ public class NettyWriteResponseFilter implements GlobalFilter, Ordered {
 			byteBuf.release();
 			return buffer;
 		}
-		throw new IllegalArgumentException("Unkown DataBufferFactory type " + bufferFactory.getClass());
+		throw new IllegalArgumentException("Unknown DataBufferFactory type " + bufferFactory.getClass());
 	}
 
 	private void cleanup(ServerWebExchange exchange) {