Warning: mysqli_fetch_array(): The result type should be either MYSQLI_NUM, MYSQLI_ASSOC or MYSQLI_BOTH in
$search_user = mysqli_fetch_array(mysqli_query
($connect,"SELECT * FROM `accounts` WHERE `nickname` = '".$plogin."' AND `password` = '".$ppass."'"), 0);
$result = mysqli_query($connect, "SELECT * FROM `accounts` WHERE `nickname` = '".$plogin."' AND `password` = '".$ppass."'");
if (mysqli_num_rows($result) == 1) {
/* типо есть аккаунт */
} else {
/* типо нет аккаунта */
}