Take health questions from active vaccines

The HPV programme has two discontinued vaccines (necessary to support
importing old vaccination records), however for new consent forms we
should make sure to get the health questions from the active vaccine to
ensure users are seeing the right information.

app/models/consent_form.rb

@@ -434,7 +434,10 @@ def reset_unused_fields
 
   def seed_health_questions
     return unless health_answers.empty?
-    vaccine = programme.vaccines.first
+
+    # TODO: handle multiple active vaccines
+    vaccine = programme.vaccines.active.first
+
     self.health_answers = vaccine.health_questions.to_health_answers
   end