Upgrade Gitlab CE from 7.1.1 to 7.14

I have Gitlab CE 7.1.1 (non omnibus … is from source) on Ubuntu 12.04 LTS with postgresql.
I have try upgrade to 7.14 with this guide: https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/update/6.x-or-7.x-to-7.14.md

But at point 7 (# Run database migrations from 6.0 to 6.1) I receive this error:

== 20130926081215 ChangeOwnerIdForGroup: reverting ============================
– change_column(:namespaces, :owner_id, :integer, {:null=>false})
rake aborted!
StandardError: An error has occurred, this and all later migrations canceled:

PG::NotNullViolation: ERROR: column “owner_id” contains null values
: ALTER TABLE “namespaces” ALTER “owner_id” SET NOT NULL/home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/activerecord-4.1.11/lib/active_record/connection_adapters/postgresql/database_statements.rb:128:in async_exec' /home/git/gitlab/vendor/bundle/ruby/2.1.0/gems/activerecord-4.1.11/lib/active_record/connection_adapters/postgresql/database_statements.rb:128:in block in execute’

Can you help me ?