Update the "Connect to server" tests for Jessie

  Scenario: Connecting to an SFTP server on the Internet using the GNOME "Connect to a Server" feature # features/ssh.feature:26
    Given I have the SSH key pair for an SFTP server                                                   # features/step_definitions/ssh.rb:36
    When I connect to an SFTP server on the Internet                                                   # features/step_definitions/ssh.rb:78
      FindFailed: can not find GnomePlacesConnectToServer.png on the screen.
      Line ?, in File ? (RuntimeError)
      features/ssh.feature:28:in `When I connect to an SFTP server on the Internet'

Feature Branch: feature/jessie

Parent Task: #7563 (closed)

Original created by @intrigeri on 10325 (Redmine)