ShareByMailProvider: getAccessList: set correct value for 'public'

PDOStatement::rowCount behavior is undefined for SELECT statements
for some database types, therefore manually set the value for 'public'
based on actual results fetched.

Signed-off-by: Adam Serbinski <adam@serbinski.com>

apps/sharebymail/lib/ShareByMailProvider.php

@@ -1108,9 +1108,10 @@ public function getAccessList($nodes, $currentAccess): array {
  ));
  $cursor = $qb->executeQuery();
 
- $public = $cursor->rowCount() > 0;
+ $public = false;
  $mail = [];
  while ($row = $cursor->fetch()) {
+ $public = true;
  if ($currentAccess === false) {
  $mail[] = $row['share_with'];
  } else {