Fix sunspot:solr:restart rake task

[jameslzhu]

It appears sunspot:solr:restart doesn't successful start solr again, and the sunspot:solr:start task must be explicitly run to do so:

$ RAILS_ENV=production bundle exec rake sunspot:solr:restart
/home/h/hk/hkn/hkn-rails/migrate/releases/20190107053052/app/controllers/admin/admin_controller.rb:12: warning: key :person is duplicated and overwritten on line 12
/home/h/hk/hkn/hkn-rails/migrate/releases/20190107053052/app/controllers/admin/admin_controller.rb:12: warning: key :person is duplicated and overwritten on line 12
Sending stop command to Solr running on port 8983 ... waiting 5 seconds to allow Jetty process 24944 to stop gracefully.
$ ps aux | grep solr
hkn      14220  0.0  0.0  12784   944 pts/4    S+   16:40   0:00 grep --color=auto solr
$ RAILS_ENV=production bundle exec rake sunspot:solr:start
/home/h/hk/hkn/hkn-rails/migrate/releases/20190107053052/app/controllers/admin/admin_controller.rb:12: warning: key :person is duplicated and overwritten on line 12
/home/h/hk/hkn/hkn-rails/migrate/releases/20190107053052/app/controllers/admin/admin_controller.rb:12: warning: key :person is duplicated and overwritten on line 12
Removing stale PID file at tmp/pids/sunspot-solr-production.pid
Successfully started Solr ...