Revert "Fix: Prevent restore cache on closing connection (ddeboer#548)"

This reverts commit 1a0a86e.

src/Connection.php

@@ -50,11 +50,9 @@ public function expunge(): bool
 
     public function close(int $flag = 0): bool
     {
-        $stream = $this->resource->getStream();
-
         $this->resource->clearLastMailboxUsedCache();
 
-        return \imap_close($stream, $flag);
+        return \imap_close($this->resource->getStream(), $flag);
     }
 
     public function getQuota(string $root = 'INBOX'): array