VPN / IPsec - cleanup non existing ca files. closes https://github.com/opnsense/core/issues/5600
VPN / IPsec - cleanup non existing ca files. closes https://github.com/opnsense/core/issues/5600

Although in theory this might remove manual added files, we don't officially support manual overwrites here and expect the user to add certificates in our store.
While here cleanup a bit of ipsec_configure_do() for readability

opnsense/core,opnsense/core,opnsense/core,opnsense/core,opnsense/core,opnsense/core