Fix typo

This if-clause is supposed to check whether an answer exists for the
current question in the local data, `answerChoices` is a different
variable.

Author: levinuss

resources/js/SessionView.svelte

@@ -262,7 +262,7 @@
         }
 
         answerChoice = data.session.answer_choices.find(e => e.question_id === currentQuestionId);
-        if (!answerChoices) {
+        if (!answerChoice) {
             return;
         }