how to avoid the appearin of <br /> at the endof echo? - php

Question

here is my code below that i use to register a user
<?php
header("Content-Type: application/json");
require_once("config.php");
if(isset($_POST["email"]) && isset($_POST["username"]) && isset($_POST["password"])){
$email = $_POST["email"];
$username = $_POST["username"];
$password = $_POST["password"];
}
$con = mysqli_connect(DATABASE_HOST, DATABASE_USERNAME, DATABASE_PASSWORD, DATABASE_NAME);
if($con){
echo "connection good";
}
$response = array();
$statement = mysqli_prepare($con, "SELECT * FROM accounts WHERE email = ? OR username = ?");
mysqli_stmt_bind_param($statement, "ss", $email, $username);
$result = mysqli_stmt_execute($statement);
$row = mysqli_num_rows($result);
if($row > 0){
$response["success"] = false;
$response["message"] = "Email or Username already exists.";
}else{
mysqli_stmt_close($statement);
$statement2 = mysqli_prepare($con, "INSERT INTO accounts (email, username, password) VALUES (?, ?, ?)");
mysqli_stmt_bind_param($statement2, "sss", $email, $username, $password);
$result2 = mysqli_stmt_execute($statement2);
$row2 = mysqli_affected_rows($statement2);
if($row2 > 0){
$response["success"] = true;
$response["message"] = "Account created successfuly.";
}else{
$response["success"] = false;
$response["message"] = "Creation error.";
}
}
$output = json_encode($response);
echo $output;
mysqli_close($con);
?>
at the end of the file when i check the localhost it echos "good connection br" which i cant use it with json .. how to avoid it so i caan use the response in jsonobject later