CVE-2017-15132: dovecot: auth client leaks memory if SASL authentication is aborted.

https://github.com/dovecot/core/commit/1a29ed2f96da1be22fa5a4d96c7583aa81b8b060

--- a/src/lib-auth/auth-client-request.c
+++ b/src/lib-auth/auth-client-request.c
@@ -186,6 +186,7 @@ void auth_client_request_abort(struct auth_client_request **_request)
 
 	auth_client_send_cancel(request->conn->client, request->id);
 	call_callback(request, AUTH_REQUEST_STATUS_ABORT, NULL, NULL);
+	pool_unref(&request->pool);
 }
 
 unsigned int auth_client_request_get_id(struct auth_client_request *request)