NEXSTEP/question_plugin — pull request #1 by tamtamchik (2014-03-25 11:38:02+00:00)
Title: Fix answering questions

I'm not sure this is base problem, but I got this error when answering the questions.

```
Rendered mailer/_issue.text.erb (3.8ms)
Rendered plugins/question_plugin/app/views/question_mailer/answered_question.text.erb within layouts/mailer (9.4ms)
Completed 500 Internal Server Error in 291.7ms

ActionView::Template::Error (undefined method `first' for nil:NilClass):
1: <%= "#{issue.tracker.name} ##{issue.id}: #{issue.subject}" %>
2: <%= issue_url %>
3:
4: <%= render_email_issue_attributes(issue, users.first) %>
5: ----------------------------------------
6: <%= issue.description %>
7:
app/views/mailer/_issue.text.erb:4:in `_app_views_mailer__issue_text_erb___195752182905986264_52251460'
app/models/mailer.rb:410:in `block in mail'
app/models/mailer.rb:409:in `mail'
app/models/mailer.rb:422:in `initialize'
app/models/mailer.rb:445:in `method_missing'
lib/redmine/hook.rb:61:in `block (2 levels) in call_hook'
lib/redmine/hook.rb:61:in `each'
lib/redmine/hook.rb:61:in `block in call_hook'
lib/redmine/hook.rb:58:in `tap'
lib/redmine/hook.rb:58:in `call_hook'
lib/redmine/hook.rb:153:in `call_hook'
app/controllers/issues_controller.rb:469:in `block in save_issue_with_child_records'
app/controllers/issues_controller.rb:458:in `save_issue_with_child_records'
app/controllers/issues_controller.rb:184:in `update'

```

So I did this change (I think it's correct though).