Update an Opencart webshop mysql extension from mysqli or PDO

Project:

Update my Opencart webshop extension to compatible up-to-date mysqli or PDO extension (but don't disable the error messages). The modification has to leave all working webshop features untouched.

The webshop adress is [url removed, login to view]

I think it is a very short easy job if you know what to do.

-

The error message in admin page:

SyntaxError: JSON.parse: unexpected character at line 1 column 1 of the JSON data

OK

<br />
<b>Deprecated</b>: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in <b>/home/gyogyito/public_html/system/database/mysql.php</b> on line <b>6</b><br />
{"country_id":"97","name":"Magyarorsz\u00e1g","iso_code_2":"HU","iso_code_3":"HUN","address_format":"{lastname} {firstname}
{company}
{postcode} {city}
{address_1}
{address_2}
{country}","postcode_required":"1","zone":[{"zone_id":"1428","country_id":"97","name":"B\u00e1cs-Kiskun","code":"BK","status":"1"},{"zone_id":"1429","country_id":"97","name":"Baranya","code":"BA","status":"1"},{"zone_id":"1430","country_id":"97","name":"B\u00e9k\u00e9s","code":"BE","status":"1"},{"zone_id":"1432","country_id":"97","name":"Borsod-Aba\u00faj-Zempl\u00e9n","code":"BZ","status":"1"},{"zone_id":"1433","country_id":"97","name":"Budapest","code":"BU","status":"1"},{"zone_id":"1434","country_id":"97","name":"Csongr\u00e1d","code":"CS","status":"1"},{"zone_id":"1438","country_id":"97","name":"Fej\u00e9r","code":"FE","status":"1"},{"zone_id":"1440","country_id":"97","name":"Gy\u0151r-Moson-Sopron","code":"GM","status":"1"},{"zone_id":"1441","country_id":"97","name":"Hajd\u00fa-Bihar","code":"HB","status":"1"},{"zone_id":"1442","country_id":"97","name":"Heves","code":"HE","status":"1"},{"zone_id":"1444","country_id":"97","name":"J\u00e1sz-Nagykun-Szolnok","code":"JN","status":"1"},{"zone_id":"1447","country_id":"97","name":"Kom\u00e1rom-Esztergom","code":"KO","status":"1"},{"zone_id":"1450","country_id":"97","name":"N\u00f3gr\u00e1d","code":"NO","status":"1"},{"zone_id":"1453","country_id":"97","name":"Pest","code":"PS","status":"1"},{"zone_id":"1454","country_id":"97","name":"Somogy","code":"SO","status":"1"},{"zone_id":"1456","country_id":"97","name":"Szabolcs-Szatm\u00e1r-Bereg","code":"SS","status":"1"},{"zone_id":"1462","country_id":"97","name":"Tolna","code":"TO","status":"1"},{"zone_id":"1463","country_id":"97","name":"Vas","code":"VA","status":"1"},{"zone_id":"1464","country_id":"97","name":"Veszpr\u00e9m","code":"VE","status":"1"},{"zone_id":"1465","country_id":"97","name":"Zala","code":"ZA","status":"1"}],"status":"1"}

MySQL PHP

Project ID: #9488615

About the project