Revert "Suppress internal errors from imap_reopen() (ddeboer#524)"

This reverts commit 1eee4d7.

src/ImapResource.php

@@ -59,14 +59,8 @@ private function initMailbox(): void
             return;
         }
 
-        \set_error_handler(static function (): bool {
-            return true;
-        });
-
         \imap_reopen($this->resource, $this->mailbox->getFullEncodedName());
 
-        \restore_error_handler();
-
         if (self::isMailboxOpen($this->mailbox, $this->resource)) {
             return;
         }