Remove backward compatibility support

software/kvm/instance-kvm.cfg.in

@@ -45,7 +45,7 @@ bytes = 4
 recipe = slapos.cookbook:kvm
 vnc-ip = $${slap-network-information:local-ipv4}
 vnc-port = 5901
-nbd-ip = $${slap-parameter:nbd-ip}
+nbd-ip = $${slap-parameter:nbd-host}
 nbd-port = $${slap-parameter:nbd-port}
 tap = $${slap-network-information:network-interface}
 disk-path = $${directory:srv}/virtual.qcow2
@@ -167,11 +167,7 @@ frontend-software-type = frontend
 frontend-software-url = http://git.erp5.org/gitweb/slapos.git/blob_plain/refs/tags/slapos-0.92:/software/kvm/software.cfg
 
 nbd-port = 1024
-nbd-ip = debian.nbd.vifib.net
-
-# backward compatibility: old style (nbd_port) can still be used.
-nbd_port = $${:nbd-port}
-nbd_ip = $${:nbd-ip}
+nbd-host = debian.nbd.vifib.net
 
 ram-size = 1024
 disk-size = 10