XenAPI: Enable linux bridge in Dom0 for neturon

When using neutron network under xenserver, we must enable linux bridge
in Dom0 as neutron will use linux bridge qbr in compute node for
security group. But by default XenServer use openvswitch and disabled
linux bridge. This patch is to remove this restriction.

Change-Id: I0e8124ff2323810fdc46c717a750ce7e8f4aa0c6

lib/nova_plugins/hypervisor-xenserver

@@ -90,6 +90,10 @@ CRONTAB
         echo "install_conntrack_tools"
     } | $ssh_dom0
 
+    if is_service_enabled neutron; then
+        # Remove restriction on linux bridge in Dom0 when neutron is enabled
+        $ssh_dom0 "rm -f /etc/modprobe.d/blacklist-bridge*"
+    fi
 }
 
 # install_nova_hypervisor() - Install external components