When a user is removed we should remove the right shares

* This means all the shares directly shared with them
* Or all group shares having a special share with them

This patch fixes the operator precedece (AND before OR).
So before this patch:

(share_with = <deleted user> AND share_type = 0) OR share_type=2

So it deleted all user specific shares

Now:
share_with = <deleted user> AND (share_type = 0 OR (share_type=2)

lib/private/share/hooks.php

@@ -38,7 +38,7 @@ class Hooks extends \OC\Share\Constants {
 	public static function post_deleteUser($arguments) {
 		// Delete any items shared with the deleted user
 		$query = \OC_DB::prepare('DELETE FROM `*PREFIX*share`'
-			.' WHERE `share_with` = ? AND `share_type` = ? OR `share_type` = ?');
+			.' WHERE `share_with` = ? AND (`share_type` = ? OR `share_type` = ?)');
 		$query->execute(array($arguments['uid'], self::SHARE_TYPE_USER, self::$shareTypeGroupUserUnique));
 		// Delete any items the deleted user shared
 		$query = \OC_DB::prepare('SELECT `id` FROM `*PREFIX*share` WHERE `uid_owner` = ?');