enable tcp_fastopen if available failed if kernel version >= 4.12

[Willian-Zhang]

purposed change

In tasks/main.yml

- name: enable tcp_fastopen if available
  sysctl:
    name: net.ipv4.tcp_fastopen
    value: 3
    state: present
    reload: yes
  when: shadowsocks_fast_open and shadowsocks_sysctl_tweak and ansible_kernel is version_compare('3.7', '>=') and ansible_kernel is version_compare('4.12', '<=')
  tags: sysctl

[sparanoid]

This project is now unmaintained. I've migrated to shadowsocks/shadowsocks-libev Docker image.