Issue description

Hi there,

Since the R3 expired certificate from September 30th, my Wickedpdf stopped working. It seems I cannot call wicked_pdf_stylesheet_link_tag, due to a certificate error.

Here is the stacktrace:

ActionView::Template::Error: SSL_connect returned=1 errno=0 state=error: certificate verify failed from /usr/local/rvm/rubies/ruby-2.3.6/lib/ruby/2.3.0/net/protocol.rb:44:in connect_nonblock’ from /usr/local/rvm/rubies/ruby-2.3.6/lib/ruby/2.3.0/net/protocol.rb:44:in ssl_socket_connect' from /usr/local/rvm/rubies/ruby-2.3.6/lib/ruby/2.3.0/net/http.rb:928:in connect’ from /usr/local/rvm/rubies/ruby-2.3.6/lib/ruby/2.3.0/net/http.rb:863:in do_start' from /usr/local/rvm/rubies/ruby-2.3.6/lib/ruby/2.3.0/net/http.rb:852:in start’ from /usr/local/rvm/rubies/ruby-2.3.6/lib/ruby/2.3.0/net/http.rb:584:in start' from /usr/local/rvm/rubies/ruby-2.3.6/lib/ruby/2.3.0/net/http.rb:479:in get_response’ from /usr/local/rvm/rubies/ruby-2.3.6/lib/ruby/2.3.0/net/http.rb:456:in get' from /usr/local/rvm/gems/ruby-2.3.6/gems/wicked_pdf-2.1.0/lib/wicked_pdf/wicked_pdf_helper/assets.rb:159:in read_from_uri’ from /usr/local/rvm/gems/ruby-2.3.6/gems/wicked_pdf-2.1.0/lib/wicked_pdf/wicked_pdf_helper/assets.rb:149:in read_asset' from /usr/local/rvm/gems/ruby-2.3.6/gems/wicked_pdf-2.1.0/lib/wicked_pdf/wicked_pdf_helper/assets.rb:20:in block in wicked_pdf_stylesheet_link_tag’ from /usr/local/rvm/gems/ruby-2.3.6/gems/wicked_pdf-2.1.0/lib/wicked_pdf/wicked_pdf_helper/assets.rb:18:in collect' from /usr/local/rvm/gems/ruby-2.3.6/gems/wicked_pdf-2.1.0/lib/wicked_pdf/wicked_pdf_helper/assets.rb:18:in wicked_pdf_stylesheet_link_tag’ from /home/app/app/views/layouts/pdf.html.erb:5:in _app_views_layouts_pdf_html_erb__4356050262088495231_58899600' from /usr/local/rvm/gems/ruby-2.3.6/gems/actionview-4.2.0/lib/action_view/template.rb:145:in block in render’ from /usr/local/rvm/gems/ruby-2.3.6/gems/activesupport-4.2.0/lib/active_support/notifications.rb:166:in instrument'

Expected or desired behavior

Not getting any certificate errors.

System specifications

Ubuntu 16.04 Docker image: phusion/passenger-ruby23:0.9.29

wicked_pdf gem version (output of cat Gemfile.lock | grep wicked_pdf):

wicked_pdf (2.1.0)

wkhtmltopdf version (output of wkhtmltopdf --version):

whtmltopdf provider gem and version if one is used:

Using gem ‘wkhtmltopdf-binary’

platform/distribution and version (e.g. Windows 10 / Ubuntu 16.04 / Heroku cedar):

Ubuntu 16.04