For now, disable persistent connections and the "max_connections" setup warning
Ref T11672. At low loads, this causes us to use more connections, which is pushing some installs over the default limits.
Rather than trying to walk users through changing max_connections, open_files_limit, fs.file-max, ulimit, etc., just put things back for now. After T11044 we should have headroom to use persistent connections within the default limits on all reasonable systems..
Test Plan: Loaded Phabricator, poked around.
Reviewed By: chad
Maniphest Tasks: T11672
Differential Revision: https://secure.phabricator.com/D16591