Revert "Allow persistent connections for HTTP PURGE (error) responses" - causing problems with vhtcpd

Revert for now, investigate later

This reverts commit be44d6fa1a2421deb5b7951e44f2dcb936ef2664.

Change-Id: I5a9f16eb52d3346394ffcdb9e39023cd3f4030d8
Merge "Revert "Allow persistent connections for HTTP PURGE (error) responses" - causing problems with vhtcpd" into production