vici: Also wipe cached PINs during clear-creds command

The PINs are not necessary anymore when we remove all loaded private keys.

Fixes: 2ceeb96db5 ("vici: Add command to load a private key from a token")

src/libcharon/plugins/vici/vici_cred.c

@@ -531,6 +531,7 @@ CALLBACK(clear_creds, vici_message_t*,
 	private_vici_cred_t *this, char *name, u_int id, vici_message_t *message)
 {
 	this->creds->clear(this->creds);
+	this->pins->clear(this->pins);
 	this->authority->clear_ca_certs(this->authority);
 	lib->credmgr->flush_cache(lib->credmgr, CERT_ANY);