confirmation email integration fixes (#434)

client/components/open/integrations/SubmissionConfirmationIntegration.vue

@@ -81,13 +81,14 @@ const emailSubmissionConfirmationHelp = computed(() => {
 
 onBeforeMount(() => {
   for (const [keyname, defaultValue] of Object.entries({
+    respondent_email: emailSubmissionConfirmationField.value !== null,
     notification_sender: "OpnForm",
     notification_subject: "We saved your answers",
     notification_body:
       "Hello there 👋 <br>This is a confirmation that your submission was successfully saved.",
     notifications_include_submission: true,
   })) {
-    if (props.integrationData.settings[keyname] === undefined) {
+    if (keyname === 'respondent_email' || props.integrationData.settings[keyname] === undefined) {
       props.integrationData.settings[keyname] = defaultValue
     }
   }