docs: fix a comment (Webklex#504)

Author: arnolem

src/Connection/Protocols/ProtocolInterface.php

@@ -129,7 +129,7 @@ public function examineFolder(string $folder = 'INBOX'): Response;
     public function folderStatus(string $folder = 'INBOX', $arguments = ['MESSAGES', 'UNSEEN', 'RECENT', 'UIDNEXT', 'UIDVALIDITY']): Response;
 
     /**
-     * Fetch message headers
+     * Fetch message contents
      * @param int|array $uids
      * @param string $rfc
      * @param int|string $uid set to IMAP::ST_UID or any string representing the UID - set to IMAP::ST_MSGN to use