title: "Ressource id #5" returned when using mysql in ssh2_exec
body: <p>I am using ssh2 to make a mysql query on a remote server.
  Here are my lines:</p>
  
  <pre><code>$connection = ssh2_connect("ip_address", 22);
  if (ssh2_auth_pubkey_file($connection, "user", ".ssh/id_rsa.pub", ".ssh/id_rsa"))
  {
  echo("Ok");
  }
  else
  {
  die("KO");
  }
  $stream = ssh2_exec($connection, "mysql -u root --password=password -D db -e 'SELECT * FROM table'");
  echo $stream;
  </code></pre>
  
  <p>When i launch my command, i have the message "OK" and the $stream variable writes : "Ressource id #5"
  I don't know why it doesn't work. I tested the command in bash, with properly ssh command :</p>
  
  <pre><code>ssh user@ip_address "command"
  </code></pre>
  
  <p>And it worked.
  I'm waiting your help,
  Thank you,
  Cordialement,</p>