mod_s2s_auth_posh: Use unused loop variable for something [luacheck] Saves a function call, shuts up luacheck. In no case does the input list of certificates not result in a list of fingerprints of equal length.

This module lets you block connections to any remote servers not on a
whitelist.

``` {.lua}
s2s_whitelist = {
    "example.org",
}
```