Upgrade from Satellite 6.2.14 to 6.3 fails with "undefined method `schema_version' for nil:NilClass" during reindex_docker_tags step

Issue

When upgrading from Satellite 6.2.14 to Satellite 6.3 the following error occurs:

Upgrade Step: reindex_docker_tags (this may take a while) ...
/usr/share/foreman/lib/tasks/repair_repos_62.rake:2: warning: already initialized constant PULP_IDS_FILE
/usr/share/foreman/lib/tasks/repair_repos.rake:2: warning: previous definition of PULP_IDS_FILE was here
rake aborted!
NoMethodError: undefined method `schema_version' for nil:NilClass
/opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.4.5.64/app/models/katello/docker_meta_tag.rb:132:in `block in get_tag_table_values'
/opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.4.5.64/app/models/katello/docker_meta_tag.rb:131:in `each'
/opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.4.5.64/app/models/katello/docker_meta_tag.rb:131:in `map'
/opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.4.5.64/app/models/katello/docker_meta_tag.rb:131:in `get_tag_table_values'
/opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.4.5.64/app/models/katello/docker_meta_tag.rb:95:in `block in import_meta_tags'
/opt/rh/rh-ror42/root/usr/share/gems/gems/activerecord-4.2.6/lib/active_record/relation/delegation.rb:46:in `each'
/opt/rh/rh-ror42/root/usr/share/gems/gems/activerecord-4.2.6/lib/active_record/relation/delegation.rb:46:in `each'
/opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.4.5.64/app/models/katello/docker_meta_tag.rb:94:in `import_meta_tags'
/opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.4.5.64/app/models/katello/docker_tag.rb:48:in `import_all'
/opt/theforeman/tfm/root/usr/share/gems/gems/katello-3.4.5.64/lib/katello/tasks/upgrades/3.4/reindex_docker_tags.rake:8:in `block (4 levels) in <top (required)>'
Tasks: TOP => katello:upgrades:3.4:reindex_docker_tags
(See full trace by running task with --trace)
foreman-rake katello:upgrades:3.4:reindex_docker_tags failed! Check the output for error!