Fix torrc.directory.erb

   - [dotterel] Warning: Variable access via 'port' is deprecated. Use '@port' instead. template[/srv/leap/puppet/modules/tor/templates/torrc.directory.erb]:2
   - [dotterel] (at /usr/lib/ruby/vendor_ruby/puppet/parser/templatewrapper.rb:76:in `method_missing')

(from redmine: created on 2016-08-16, closed on 2016-08-31, blocks #8415 (closed))