gitlab-omnibus restore issues one ERROR and four WARNINGs related to psql

When restoring gitlab, the following ERROR and WARNINGS are issued:

psql:/var/opt/gitlab/backups/db/database.sql:22: ERROR:  must be owner of extension plpgsql
psql:/var/opt/gitlab/backups/db/database.sql:2931: WARNING:  no privileges could be revoked for "public" (two occurences)
psql:/var/opt/gitlab/backups/db/database.sql:2933: WARNING:  no privileges were granted for "public" (two occurences)

This is what I did:

1. Installed gitlab_7.8.4-omnibus-1_amd64.deb on Ubuntu 14.04 server 64-bit.

2. Signed up for an account and confirmed.

3. Created a test project with a README.md and a home page in the wiki, all via the web interface.

4. Backed up:

   $ sudo gitlab-rake gitlab:backup:create
   Dumping database ... 
   Dumping PostgreSQL database gitlabhq_production ... [DONE]
   done
   Dumping repositories ...
    * janne/test ... [DONE]
    * janne/test.wiki ...  [DONE]
   done
   Dumping uploads ... 
   done
   Creating backup archive: 1426587404_gitlab_backup.tar ... done
   Uploading backup archive to remote storage  ... skipped
   Deleting tmp directories ... done
   Deleting old backups ... skipping
   $

5. Restored:

   $ sudo gitlab-ctl stop unicorn
   ok: down: unicorn: 0s, normally up
   $ sudo gitlab-ctl stop sidekiq
   ok: down: sidekiq: 0s, normally up
   $ sudo gitlab-rake gitlab:backup:restore BACKUP=1426587404
   [sudo] password for janne: ******
   Unpacking backup ... done
   Restoring database ... 
   Restoring PostgreSQL database gitlabhq_production ... SET
   SET
   SET
   SET
   SET
   CREATE EXTENSION
   psql:/var/opt/gitlab/backups/db/database.sql:22: ERROR:  must be owner of extension plpgsql
   SET
   SET
   SET
   CREATE TABLE
   ALTER TABLE
   CREATE SEQUENCE
   <lines removed>
   CREATE INDEX
   CREATE INDEX
   CREATE INDEX
   psql:/var/opt/gitlab/backups/db/database.sql:2931: WARNING:  no privileges could be revoked for "public"
   REVOKE
   psql:/var/opt/gitlab/backups/db/database.sql:2932: WARNING:  no privileges could be revoked for "public"
   REVOKE
   psql:/var/opt/gitlab/backups/db/database.sql:2933: WARNING:  no privileges were granted for "public"
   GRANT
   psql:/var/opt/gitlab/backups/db/database.sql:2934: WARNING:  no privileges were granted for "public"
   GRANT
   [DONE]
   done
   Restoring repositories ...
    * janne/test ... [DONE]
    * janne/test.wiki ...  [DONE]
   Put GitLab hooks in repositories dirs [DONE]
   done
   Restoring uploads ... 
   done
   This will rebuild an authorized_keys file.
   You will lose any data stored in authorized_keys file.
   Do you want to continue (yes/no)? yes
   
   Deleting tmp directories ... done
   $

My gitlab.rb looks like this:

external_url 'https://my.domain:8443'

nginx['custom_gitlab_server_config'] = 'ssl_client_certificate /etc/ssl/certs/my.ca.pem;
  ssl_verify_client on;'
nginx['ssl_certificate'] = '/etc/ssl/certs/my.localhost.crt'
nginx['ssl_certificate_key'] = '/etc/ssl/private/my.localhost.key'

I could not run the GitLab Application Check. It seems that it does not apply to gitlab-omnibus:

$ sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true
sudo: bundle: command not found
$