Fix: Trying to access array offset on value of type null in php ^7.3

[gibrandev]

First

    <br/><b>Notice</b>:  Trying to access array offset on value of type null in <b>D:\laragon\www\popoji\po-content\filemanager\UploadHandler.php</b>on line<b>497</b><br />{
    "files": [
        {
            "name": "img_6671-awan-1-scaled.jpg",
            "size": 689636,
            "type": "image\/jpeg",
            "url": "http:\/\/popoji.test\/po-content\/filemanager\/upload.php\/po-content\/uploads\/img_6671-awan-1-scaled.jpg",
            "deleteUrl": "http:\/\/popoji.test\/po-content\/filemanager\/upload.php?file=img_6671-awan-1-scaled.jpg",
            "deleteType": "DELETE"
        }
    ]
    }

Second

<br/><b>Notice</b>:  Trying to access array offset on value of type null in <b>D:\laragon\www\popoji\po-content\filemanager\UploadHandler.php</b>on line<b>1431</b><br />{
    "files": [
        {
            "name": "img_6671-awan-1-scaled (1).jpg",
            "size": 689636,
            "type": "image\/jpeg",
            "url": "http:\/\/popoji.test\/po-content\/filemanager\/upload.php\/po-content\/uploads\/img_6671-awan-1-scaled%20%281%29.jpg",
            "deleteUrl": "http:\/\/popoji.test\/po-content\/filemanager\/upload.php?file=img_6671-awan-1-scaled%20%281%29.jpg",
            "deleteType": "DELETE"
        }
    ]
}