fix(Sharing): Remove faulty check if required properties have a default value

Signed-off-by: provokateurin <kate@provokateurin.de>

Author: provokateurin

lib/private/Sharing/SharingRegistry.php

@@ -175,10 +175,6 @@ public function getPropertyTypeCompatibleRecipientTypes(): array {
 	public function registerPropertyType(ISharePropertyType $propertyType): void {
 		$class = $propertyType::class;
 
-		if ($propertyType->isRequired() && $propertyType->getDefaultValue() === null) {
-			throw new RuntimeException('Share property type ' . $class . ' is required, but has no default value.');
-		}
-
 		if (isset($this->propertyTypes[$class])) {
 			throw new RuntimeException('Share property type ' . $class . ' is already registered');
 		}