message: remove hiredis
diff: -[submodule "thirdparty/hiredis"]
  - path = thirdparty/hiredis
  - url = https://github.com/redis/hiredis.git
  [submodule "thirdparty/nghttp2"]
  path = thirdparty/nghttp2
  url = https://github.com/nghttp2/nghttp2.git
  