Fix #908: cleanup OVS ports in tap_unplug

tap_unplug() is only called in hotplugging functions which
perform a tap_plug() afterwards, and and in qemu-server's
bridge-down script.
The OVS port cleanup for non-firewall ports was done only in
tap_plug(), which means that in the case when qemu exits and
the tap device disappears, the OVS port for it stays.

With this patch the cleanup happens in both tap_unplug() and
tap_plug() to avoid problems with upgrades on systems
where there have already been ports leaked.

src/PVE/Network.pm

@@ -371,6 +371,8 @@ sub tap_unplug {
     }
     
     &$cleanup_firewall_bridge($iface);
+    #cleanup old port config from any openvswitch bridge
+    eval {run_command("/usr/bin/ovs-vsctl del-port $iface", outfunc => sub {}, errfunc => sub {}) };
 }
 
 sub copy_bridge_config {