Revert "Fix sync errors for duplicate cards with the same UID for dif…

…ferent backends"

This reverts commit ddcee3d.

Signed-off-by: Christopher Ng <chrng8@gmail.com>

apps/dav/lib/CardDAV/Converter.php

@@ -47,14 +47,12 @@ public function createCardFromUser(IUser $user): ?VCard {
 		$userProperties = $this->accountManager->getAccount($user)->getProperties();
 
 		$uid = $user->getUID();
-		$backendClassName = $user->getBackendClassName();
 		$cloudId = $user->getCloudId();
 		$image = $this->getAvatarImage($user);
 
 		$vCard = new VCard();
 		$vCard->VERSION = '3.0';
-		$vCard->UID = md5("$backendClassName:$uid");
-	 	$vCard->add(new Text($vCard, 'X-NEXTCLOUD-UID', $uid));
+		$vCard->UID = $uid;
 
 		$publish = false;
 

apps/dav/lib/CardDAV/SyncService.php

@@ -274,7 +274,7 @@ public function syncInstance(\Closure $progressCallback = null) {
 		$allCards = $this->backend->getCards($systemAddressBook['id']);
 		foreach ($allCards as $card) {
 			$vCard = Reader::read($card['carddata']);
-			$uid = isset($vCard->{'X-NEXTCLOUD-UID'}) ? $vCard->{'X-NEXTCLOUD-UID'}->getValue() : $vCard->UID->getValue();
+			$uid = $vCard->UID->getValue();
 			// load backend and see if user exists
 			if (!$this->userManager->userExists($uid)) {
 				$this->deleteUser($card['uri']);