message: Fix mysql auth dispatch null pointer.
diff: @@ -498,9 +498,9 @@ static void mysql_sha2_password_with_nonce(char* ret, char* nonce, char* passwor
  */
  static int mysql_auth_encrypt_dispatch(char *buf, char *auth_plugin_name, char *password, zend_size_t password_len, char* nonce, int *next_state)
  {
  - if (strcasecmp("mysql_native_password", auth_plugin_name) == 0)
  + if (!auth_plugin_name || strcasecmp("mysql_native_password", auth_plugin_name) == 0)
  {
  - // if not native, skip password and will trigger the auth switch
  + // mysql_native_password is default
  // auth-response
  char hash_0[20];
  bzero(hash_0, sizeof (hash_0));
  