networkmanager_strongswan: 1.4.1 -> 1.4.3

Semi-automatic update generated by https://github.com/ryantm/nix-update tools. These checks were done:

- built on NixOS
- Warning: no binary found that responded to help or version flags. (This warning appears even if the package isn't expected to have binaries.)
- found 1.4.3 with grep in /nix/store/y2jkp10za0xpb7slalbfp3qyh9sgls70-NetworkManager-strongswan-1.4.3
- directory tree listing: https://gist.github.com/3d79a64230389ed5f84ff788ad4c56f1