src/Hans/Config.hs: workaround haddock failure
src/Hans/Config.hs: workaround haddock failure

haddock failed as:
  src/Hans/Config.hs:95:27: error:
      parse error on input ‘-- ^ 1500 - (max (20 for IPv4) (60 for IPv6)
                            --          + 60 for maximum TCP header)’

Add more whitespace to avoid it.

Signed-off-by: Sergei Trofimovich <df7d2cee2e7ececeb2368216a0f9d0537fd32149@google.com>

cartazio/HaNS,cartazio/HaNS,GaloisInc/HaNS,GaloisInc/HaNS