ovs-monitor-ipsec fails in StrongSwanHelper.get_active_conns()

It relies on the output of ipsec status, see log:

2019-09-28T20:17:09.999Z | 1125| ovs-monitor-ipsec | INFO | Tunnel tun appeared in OVSDB
2019-09-28T20:17:10.0.5Z | 1127| ovs-monitor-ipsec | INFO | Refreshing StrongSwan configuration
2019-09-28T20:17:10.11.Z | 1128| ovs-monitor-ipsec | ERR | traceback
Traceback (most recent call last):
  File "/usr/share/openvswitch/scripts/ovs-monitor-ipsec", line 1238, in <module>
    main()
  File "/usr/share/openvswitch/scripts/ovs-monitor-ipsec", line 1225, in main
    monitor.run()
  File "/usr/share/openvswitch/scripts/ovs-monitor-ipsec", line 1095, in run
    self.ike_helper.refresh(self)
  File "/usr/share/openvswitch/scripts/ovs-monitor-ipsec", line 351, in refresh
    conns_dict = self.get_active_conns()
  File "/usr/share/openvswitch/scripts/ovs-monitor-ipsec", line 261, in get_active_conns
    tunnel_name = line.split(":")
TypeError: a bytes-like object is required, not 'str'

# ipsec status
Routed Connections:
       tun-1{1}:  ROUTED, TRANSPORT, reqid 1
       tun-1{1}:   192.168.1.112/32[gre] === 192.168.1.111/32[gre]
Security Associations (0 up, 0 connecting):
  none