Apply Layout/LineLength rubocop rule

Note we're excluding a few files:

* Configuration files that weren't generated by us
* Migration files that weren't generated by us
* The Gemfile, since it includes an important comment that must be on
  the same line as the gem declaration
* The Budget::Stats class, since the heading statistics are a mess and
  having shorter lines would require a lot of refactoring

app/helpers/comments_helper.rb

@@ -21,9 +21,17 @@ module CommentsHelper
 
   def comment_button_text(parent_id, commentable)
     if commentable.class == Legislation::Question
-      parent_id.present? ? t("comments_helper.reply_button") : t("legislation.questions.comments.comment_button")
+      if parent_id.present?
+        t("comments_helper.reply_button")
+      else
+        t("legislation.questions.comments.comment_button")
+      end
     else
-      parent_id.present? ? t("comments_helper.reply_button") : t("comments_helper.comment_button")
+      if parent_id.present?
+        t("comments_helper.reply_button")
+      else
+        t("comments_helper.comment_button")
+      end
     end
   end