[DRE-maint] Bug#955618: Settings -> Active Sessions gives 500 error

[Pirate Praveen]

Package: gitlab
Version: 12.8.8-5
Severity: important

Thanks to rovonovo_zoro for the report.

Started GET "/profile/active_sessions" for 192.168.122.1 at 2020-04-03 
13:34:10 +0000
Processing by Profiles::ActiveSessionsController#index as HTML
Completed 500 Internal Server Error in 46ms (ActiveRecord: 2.3ms | 
Elasticsearch: 0.0ms | Allocations: 20615)

ActionView::Template::Error (no implicit conversion of 
Rack::Session::SessionId into String):
    27:
    28: - unless is_current_session
    29: .float-right
    30: = link_to 
profile_active_session_path(active_session.public_id), data: { confirm: 
_('Are you sure? The device will be signed out of GitLab.') }, method: 
:delete, class: "btn btn-danger prepend-left-10" do
    31: %span.sr-only= _('Revoke')
    32: = _('Revoke')

/usr/lib/ruby/vendor_ruby/encryptor.rb:97:in `update'
/usr/lib/ruby/vendor_ruby/encryptor.rb:97:in `crypt'
/usr/lib/ruby/vendor_ruby/encryptor.rb:36:in `encrypt'
lib/gitlab/crypto_helper.rb:19:in `aes256_gcm_encrypt'
app/models/active_session.rb:27:in `public_id'
app/views/profiles/active_sessions/_active_session.html.haml:30
actionview (6.0.2.1) lib/action_view/base.rb:274:in `_run'
actionview (6.0.2.1) lib/action_view/template.rb:185:in `block in 
render'
activesupport (6.0.2.1) lib/active_support/notifications.rb:182:in 
`instrument'