title: Wordpress - The ssh2 PHP extension is not available
body: <p>I use SSH keys in my wp-config since a long time. Updates, plugin installation and removal, all worked well. After the last apt-get update wp is asking for the FTP password when I try to install for example a plugin.
  There was no change done to the wp installation nor the file or directory permissions. I did not update wp either.</p>
  
  <pre><code>define('FTP_PUBKEY','/home/wp-user/wp_rsa.pub');
  define('FTP_PRIKEY','/home/wp-user/wp_rsa');
  define('FTP_USER','wp-user'); define('FTP_PASS','');
  define('FTP_HOST','127.0.0.1:22');
  </code></pre>
  
  <p>Ubuntu 14.04
  WORDPRESS VERSION: 4.7.6</p>
  
  <p>PHP VERSION: 5.5.9-1ubuntu4.22</p>
  
  <p>WEB SERVER INFO: Apache/2.4.7 (Ubuntu) OpenSSL/1.0.1f
  <a href="https://i.stack.imgur.com/rucsb.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/rucsb.png" alt="enter image description here"></a></p>
  
  <p>EDIT:</p>
  
  <p>I added below to my wp-config to see if it changes something.</p>
  
  <blockquote>
    <p>define('FS_METHOD', 'ssh2');</p>
  </blockquote>
  
  <p>No I'm getting a different error message in the WP backend:
  <strong>The ssh2 PHP extension is not available</strong></p>
  
  <p>...but ssh2 is installed and loaded:</p>
  
  <pre><code># php -m |grep ssh2
  ssh2
  </code></pre>