rudder-slapd may break on upgrade when restarting on openVZ
Happened on a debian with openvz.
During an upgrade of rudder-inventory-ldap a force-reload command is issued on the rudder-slapd service.
This command kills slapd then restarts it.
The restart is fast and the slapd socket is not properly released by the kernel.
A sleep must be done before restarting to let the kernel recycle the socket.