fix: Handle email with no subject line and no body (#2164)

* fix: Add a default email subject line if no subject is present

* Add a default on the frontend

Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>

app/javascript/dashboard/components/widgets/conversation/ConversationCard.vue

@@ -30,11 +30,13 @@
         <span v-if="lastMessageInChat.content">
           {{ parsedLastMessage }}
         </span>
-        <span v-else-if="!lastMessageInChat.attachments">{{ ` ` }}</span>
-        <span v-else>
+        <span v-else-if="lastMessageInChat.attachments">
           <i :class="`small-icon ${this.$t(`${attachmentIconKey}.ICON`)}`"></i>
           {{ this.$t(`${attachmentIconKey}.CONTENT`) }}
         </span>
+        <span v-else>
+          {{ $t('CHAT_LIST.NO_CONTENT') }}
+        </span>
       </p>
       <p v-else class="conversation--message">
         <i class="ion-android-alert"></i>