Fix for array_key_exists(): Using array_key_exists() on objects is deprecated. Use isset() or property_exists() instead in /htdocs/Ip/Internal/Translations/JsonLoader.php:48

[HeinOpal]

Thank you @unyfolk for this fix

$textDomain = new TextDomain($messages);

->> if (array_key_exists('', $textDomain)) {
if (isset($textDomain['']['plural_forms'])) {
$textDomain->setPluralRule(
PluralRule::fromString($textDomain['']['plural_forms'])
);
}

$textDomain = new TextDomain($messages);
--> if (isset($textDomain[''])) {
if (isset($textDomain['']['plural_forms'])) {
$textDomain->setPluralRule(
PluralRule::fromString($textDomain['']['plural_forms'])
);
}