fix(ffresty): Set the correct maxIdleConnHosts value and idleTimeout

[onelapahead]

Fixes two different typos that affect HTTP client performance by default:

1. we meant for the idle timeout to be <5s , but not less than 500ms. Meaning we essentially don't re-use connections unless theres constant requests
2. we were setting maxidleconnsperhost == maxconnsperhost, so it wasn't actually being set to 100, meaning it kept using Go's conservative default of 2 (which I tried to fix in [ffresty] maxIdleConnsPerHost Setting #154 originally)

[EnriqueL8]

Thanks for catching these @onelapahead !