Since version 5.5.1, different keys can be put together in
/etc/swanctl/private.
See:
* tobiasbrunner@7caba2eb5524be6b51943bcc3d2cb0e4c5ecc09a
swanctl: Add 'private' directory/section to load any type of private key
Signed-off-by: Liu Qun (liuqun) <[email protected]>
