Error after update from 5.0 to 5.1

Created by: ghost

Hi i followed the update instructions and after that gitlab does not start and exit with following error

Puma 2.0.0.b7 starting...
* Min threads: 0, max threads: 16
* Environment: production
* Listening on unix:///home/git/gitlab/tmp/sockets/gitlab.socket
/home/git/gitlab/vendor/bundle/ruby/1.9.1/gems/puma-2.0.0.b7/lib/puma/binder.rb:234:in `initialize': Address already in use - /home/git/gitlab/tmp/sockets/gitlab.socket (Errno::EADDRINUSE)
    from /home/git/gitlab/vendor/bundle/ruby/1.9.1/gems/puma-2.0.0.b7/lib/puma/binder.rb:234:in `new'
    from /home/git/gitlab/vendor/bundle/ruby/1.9.1/gems/puma-2.0.0.b7/lib/puma/binder.rb:234:in `add_unix_listener'
    from /home/git/gitlab/vendor/bundle/ruby/1.9.1/gems/puma-2.0.0.b7/lib/puma/binder.rb:96:in `block in parse'
    from /home/git/gitlab/vendor/bundle/ruby/1.9.1/gems/puma-2.0.0.b7/lib/puma/binder.rb:64:in `each'
    from /home/git/gitlab/vendor/bundle/ruby/1.9.1/gems/puma-2.0.0.b7/lib/puma/binder.rb:64:in `parse'
    from /home/git/gitlab/vendor/bundle/ruby/1.9.1/gems/puma-2.0.0.b7/lib/puma/cli.rb:414:in `run_single'
    from /home/git/gitlab/vendor/bundle/ruby/1.9.1/gems/puma-2.0.0.b7/lib/puma/cli.rb:402:in `run'
    from /home/git/gitlab/vendor/bundle/ruby/1.9.1/gems/puma-2.0.0.b7/bin/puma:10:in `<top (required)>'
    from /home/git/gitlab/vendor/bundle/ruby/1.9.1/bin/puma:23:in `load'
    from /home/git/gitlab/vendor/bundle/ruby/1.9.1/bin/puma:23:in `<main>'