Description of problem:

OVS IPsec functionality does not work with libreswan when using self-signed certificates. 

When configuring OVS to use self-signed certificates for IPsec encryption, "ovs-pki" sets the CN of the cert to the name specified as part of the ovs-pki command: `ovs-pki req -u <name>`. However, when the "ovs-monitor-ipsec" daemon loads certificates and keys into libreswan, it prefixes the cert nickname with "ovs_cert" and "ovs_certkey" respectively. Which can be seen by running the command:

`$ sudo certutil -d sql:/etc/ipsec.d -L

Certificate Nickname                                         Trust Attributes
                                                             SSL,S/MIME,JAR/XPI

ovs_certkey_host_2                                           u,u,u
ovs_cert_host_1                                              P,P,P
`

The causes libreswan to fail when it tries to establish a tunnel with an error of the type:

pluto[1790412]: Failed to add connection "tun-1" with invalid "left" certificate
pluto[1790412]: failed to find certificate named 'host_2' in the NSS database

How reproducible:

Always

Steps to Reproduce:

Follow the tutorial at https://docs.openvswitch.org/en/latest/tutorials/ipsec/ using the section "2: Using self-signed certificate:"

Actual results:

Traffic is not encrypted.

Expected results:

Traffic is encrypted.