Revert "Set Memcached retry_timeout to -1"

Possibly implicated in pmtpa Apaches timing out.

This reverts commit b6b839e989aca743de073b5b366f73baead0c949.

Change-Id: Iac9f512097a9669227685b06619e4e50042e4950
Merge "Revert "Set Memcached retry_timeout to -1""