Revert ee6bc94.

The client code is not affected by the use case described in the relevant commit.
Therefore such a problem is most likely to be solved at the application level.

Author: rybakit

src/Connection/Connection.php

@@ -27,7 +27,7 @@ interface Connection
     public function open() : Greeting;
 
     /**
-     * Closes an opened connection (including a persistent one).
+     * Closes an opened connection.
      */
     public function close() : void;
 

src/Connection/StreamConnection.php

@@ -119,12 +119,6 @@ public function open() : Greeting
 
     public function close() : void
     {
-        // To close a previously opened persistent connection,
-        // we need to obtain its stream handler first
-        if (!$this->stream && $this->options['persistent']) {
-            $this->open();
-        }
-
         if ($this->stream) {
             /** @psalm-suppress InvalidPropertyAssignmentValue */
             \fclose($this->stream);