added mysql database value to dotenv

.env.example

@@ -0,0 +1,5 @@
+MYSQL_PORT=
+MYSQL_USER=
+MYSQL_PASSWORD=
+MYSQL_DATABASE=
+RIOT_API_KEY=

public/util/mysql_connect.php

@@ -8,7 +8,7 @@ class MySQLConnection {
     private string $host;
     private string $user;
     private string $pass;
-    private string $dbName = "uem";
+    private string $dbName;
     private mysqli $mysqli;
 
     public function __construct() {
@@ -16,6 +16,7 @@ class MySQLConnection {
         $this->port = intval($_ENV['MYSQL_PORT']);
         $this->user = $_ENV['MYSQL_USER'];
         $this->pass = $_ENV['MYSQL_PASSWORD'];
+		$this->dbName = $_ENV['MYSQL_DATABASE'];
         $this->createConn();
     }