Fix broken translations for Poll::Question::Answer model

Poll::QuestionAnswer model was renamed to Poll::Question::Answer
which made the previous I18n keys unavailable for the views

See PR #1977, commit 461410a

config/locales/en/activerecord.yml

@@ -213,7 +213,7 @@ en:
       image:
         title: Title
         attachment: Attachment
-      poll/question_answer:
+      poll/question/answer:
         title: "Answer"
         description: "Description"
     errors:

config/locales/es/activerecord.yml

@@ -207,7 +207,7 @@ es:
       image:
         title: Título
         attachment: Archivo adjunto
-      poll/question_answer:
+      poll/question/answer:
         title: "Respuesta"
         description: "Descripción"
     errors:

config/locales/fr/activerecord.yml

@@ -147,7 +147,7 @@ fr:
         name: Nom
         locale: Langue
         body: Contenu
-      poll/question_answer:
+      poll/question/answer:
         title: "Réponse"
         description: "Description"
     errors: