Fix sign up button not saying sign up when invite is used (#10623)

Fix #10616

app/views/auth/registrations/new.html.haml

@@ -36,6 +36,6 @@
     = f.input :agreement, as: :boolean, wrapper: :with_label, label: t('auth.checkbox_agreement_html', rules_path: about_more_path, terms_path: terms_path)
 
   .actions
-    = f.button :button, sign_up_message, type: :submit
+    = f.button :button, @invite.present? ? t('auth.register') : sign_up_message, type: :submit
 
 .form-footer= render 'auth/shared/links'