testing: Load kdf plugin in all scenarios that require it

Once we use plugin-provided prf+() these won't work otherwise.

testing/tests/sql/multi-level-ca/hosts/carol/etc/strongswan.conf

@@ -6,5 +6,5 @@ charon {
       database = sqlite:///etc/db.d/ipsec.db
     }
   }
-  load = random nonce aes sha1 sha2 pem pkcs1 gmp x509 curl revocation hmac vici kernel-netlink socket-default updown sqlite sql
+  load = random nonce aes sha1 sha2 pem pkcs1 gmp x509 curl revocation hmac kdf vici kernel-netlink socket-default updown sqlite sql
 }

testing/tests/sql/multi-level-ca/hosts/dave/etc/strongswan.conf

@@ -6,5 +6,5 @@ charon {
       database = sqlite:///etc/db.d/ipsec.db
     }
   }
-  load = random nonce aes sha1 sha2 pem pkcs1 gmp x509 curl revocation hmac vici kernel-netlink socket-default updown sqlite sql
+  load = random nonce aes sha1 sha2 pem pkcs1 gmp x509 curl revocation hmac kdf vici kernel-netlink socket-default updown sqlite sql
 }

testing/tests/sql/multi-level-ca/hosts/moon/etc/strongswan.conf

@@ -6,5 +6,5 @@ charon {
       database = sqlite:///etc/db.d/ipsec.db
     }
   }
-  load = random nonce aes sha1 sha2 pem pkcs1 gmp x509 curl revocation hmac vici kernel-netlink socket-default updown sqlite sql
+  load = random nonce aes sha1 sha2 pem pkcs1 gmp x509 curl revocation hmac kdf vici kernel-netlink socket-default updown sqlite sql
 }