perf(carddav): don't query circle memberships

It is not possible to share address books with circles so it is
pointless to query for address books shared with joined circles.

Signed-off-by: Richard Steinmetz <richard@steinmetz.cloud>

Author: st3iny

apps/dav/lib/CardDAV/CardDavBackend.php

@@ -127,7 +127,6 @@ public function getAddressBooksForUser($principalUri) {
 
 			// query for shared addressbooks
 			$principals = $this->principalBackend->getGroupMembership($principalUriOriginal, true);
-			$principals = array_merge($principals, $this->principalBackend->getCircleMembership($principalUriOriginal));
 
 			$principals[] = $principalUri;