Create a separate listen address when opening commit editor

[tarsobcaldas]

When trying to commit, I'm not able to open the editor for the commit message because of an already neovim server being set. The solution I found was to alter the shell_cmd variable in client.lua to

  local shell_cmd = {
    nvim_path,
    "--listen",
    "neogit-editor",
    "--headless",
    "--clean",
    "--noplugin",
    "-n",
    "-R",
    "-c",
    runtimepath_cmd,
    "-c",
    lua_cmd,
  }

Another option would be to have a configurable shell_cmd for the editor in the configs.