WL#16269 OpenID Connect (Oauth2 - JWT) Authentication Support

[post-push fix]
The plugin option id-token-file is remembered between sessions.
ID token is like a password and it should be freed once it is no longer
needed.

Approved by: Miroslav Rajcic <miroslav.rajcic@oracle.com>

Author: Samar Pratap Singh

libmysql/authentication_openid_connect_client/authentication_openid_connect_client_plugin.cc

@@ -129,6 +129,7 @@ static int openid_connect_authentication_client_plugin(MYSQL_PLUGIN_VIO *vio,
   std::string token, id_token_file(s_id_token_location);
   // Check if the file exists
   const int fd = open(filename, O_RDONLY);
+  free_plugin_option(s_id_token_location);
   if (fd == -1) {
     log_error("Unable to open ID token file: " + id_token_file);
     return CR_AUTH_USER_CREDENTIALS;