delayed jobs use active_record as backend

addressing:
/opt/rh/ruby193/root/usr/share/gems/gems/delayed_job-3.0.2/lib/delayed/worker.rb:75:in `before_fork': undefined method `before_fork' for nil:NilClass (NoMethodError)
        from /opt/rh/ruby193/root/usr/share/gems/gems/delayed_job-3.0.2/lib/delayed/command.rb:86:in `run_process'
        from /opt/rh/ruby193/root/usr/share/gems/gems/delayed_job-3.0.2/lib/delayed/command.rb:80:in `block in daemonize'
        from /opt/rh/ruby193/root/usr/share/gems/gems/delayed_job-3.0.2/lib/delayed/command.rb:78:in `times'
        from /opt/rh/ruby193/root/usr/share/gems/gems/delayed_job-3.0.2/lib/delayed/command.rb:78:in `daemonize'
        from script/delayed_job:5:in `<main>'
Merge pull request #1886 from xsuchy/pull-req-jobs84

delayed jobs use active_record as backend