Step katello:upgrades:3.0:add_export_distributor hangs when performing upgrade from Satellite 6.1 to 6.2

Issue

• Step katello:upgrades:3.0:add_export_distributor hangs when performing upgrade from Satellite 6.1 to 6.2

After some time following error can appear as well:

[root@satellite]# time foreman-rake katello:upgrades:3.0:add_export_distributor --verbose
Refreshing existing repositories to add export distributor
rake aborted!
There was an issue with the backend service pulp: Connection reset by peer - SSL_connect
/opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.0.0.170/app/lib/actions/middleware/backend_services_check.rb:17:in `block in plan'
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