Cast query result to int

Else we never create the default address book

apps/dav/lib/CalDAV/CalDavBackend.php

@@ -152,7 +152,7 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 			$query->andWhere($query->expr()->neq('uri', $query->createNamedParameter(BirthdayService::BIRTHDAY_CALENDAR_URI)));
 		}
 
-		return $query->execute()->fetchColumn();
+		return (int)$query->execute()->fetchColumn();
 	}
 
 	/**

apps/dav/lib/CardDAV/CardDavBackend.php

@@ -111,7 +111,7 @@ class CardDavBackend implements BackendInterface, SyncSupport {
 			->from('addressbooks')
 			->where($query->expr()->eq('principaluri', $query->createNamedParameter($principalUri)));
 
-		return $query->execute()->fetchColumn();
+		return (int)$query->execute()->fetchColumn();
 	}
 
 	/**