R1:38b10f05a224

For now, disable persistent connections and the "max_connections" setup warning

Summary:
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…