Bug#815319: Fix for upgrade process

Ignore my previous message -- Seems my testing was done with INTERFACES being set in /etc/defaults/isc-dhcp-server... (whoops!) After reverting my configs/init.d scripts to the originals, and more thorough testing, I've determined adding the below code in /etc/init.d/isc-dhcp-server after line

Bug#815319: Fix for upgrade process

I believe the broken upgrade is due to a scoping issue when $INTERFACESv4 isn't defined in /etc/defaults/isc-dhcp-server ($DHCPD_DEFAULT). To fix the upgrade process an update is needed to the /etc/init.d/isc-dhcp-server file on 4.3.4-1 to define $INTERFACESv4 before sourcing $DHCPD_DEFAULT, eg