Revert "hhvm: set nofile limit to unlimited"

This reverts commit efef205699b71ede22708e04dbf6dfdb6d731661.

Change-Id: Ib87e05bd2b9c2d4efe194703b8f8b9b2977b931f
Merge "Revert "hhvm: set nofile limit to unlimited"" into production