Fixes #36755 - Send full certificate chain to clients

Add option SSLExtraChainCert to the Webrick webserver, so the full
certificate chain is sent to clients during the SSL handkshake.

lib/launcher.rb

@@ -95,6 +95,7 @@ def https_app(https_port, plugins = https_plugins)
         :SSLVerifyClient => OpenSSL::SSL::VERIFY_PEER,
         :SSLPrivateKey => load_ssl_private_key(settings.ssl_private_key),
         :SSLCertificate => load_ssl_certificate(settings.ssl_certificate),
+        :SSLExtraChainCert => File.open(settings.foreman_ssl_ca).read.each_line.slice_after(/END CERTIFICATE/).map(&:join).map { |pem| OpenSSL::X509::Certificate.new(pem) },
         :SSLCACertificateFile => settings.ssl_ca_file,
         :SSLOptions => ssl_options,
         :SSLCiphers => CIPHERS - Proxy::SETTINGS.ssl_disabled_ciphers,