Fix spelling

templates/email/referee_in_response_to_decision_html.html

 <h3>Dear {{invitation.referee.get_title_display}} {{invitation.referee.user.last_name}},</h3>
 
 <p>
-    We hereby confirm your choice to {% if invitation.accepted %}accepte{% else %}decline (due to reason: {{invitation.get_refusal_reason_display}}){% endif %} to referee Submission
+    We hereby confirm your choice to {% if invitation.accepted %}accept{% else %}decline (due to reason: {{invitation.get_refusal_reason_display}}){% endif %} to referee Submission
 </p>
 <p>
     "<span style="color: grey;">{{invitation.submission.title}} by {{invitation.submission.author_list}}</span>".