readme: update the server requirement
@@ -20,7 +20,7 @@ $ sudo h2olog -p $(pgrep -o h2o)
## Requirements
-- H2O server built after [886db137](https://github.com/h2o/h2o/pull/2057/commits/886db13791bb03794901710974fb52cd1238968e)
+- H2O server built after [53e1db42](https://github.com/h2o/h2o/commit/53e1db428772460534191d1c35c79a6dd94e021f)
- [BCC](https://iovisor.github.io/bcc/) (BPF Compiler Collection) [installed](https://github.com/iovisor/bcc/blob/master/INSTALL.md) on your system
- Root privilege to execute the program
