Show empty content when all messages expired

[nickvergessen]

Fix #7919

Patch for testing:

diff --git a/lib/Model/Message.php b/lib/Model/Message.php
index d888d0133..5e8202961 100644
--- a/lib/Model/Message.php
+++ b/lib/Model/Message.php
@@ -192,7 +192,7 @@ class Message {
                        'isReplyable' => $this->isReplyable(),
                        'referenceId' => (string) $this->getComment()->getReferenceId(),
                        'reactions' => $reactions,
-                       'expirationTimestamp' => $expireDate ? $expireDate->getTimestamp() : 0,
+                       'expirationTimestamp' => time() + 5, //$expireDate ? $expireDate->getTimestamp() : 0,
                ];
 
                if ($this->getMessageType() === ChatManager::VERB_MESSAGE_DELETED) {
diff --git a/src/components/MessagesList/MessagesList.vue b/src/components/MessagesList/MessagesList.vue
index 0bd7b689d..293fa616c 100644
--- a/src/components/MessagesList/MessagesList.vue
+++ b/src/components/MessagesList/MessagesList.vue
@@ -272,7 +272,7 @@ export default {
                 */
                this.expirationInterval = window.setInterval(() => {
                        this.removeExpiredMessagesFromStore()
-               }, 30000)
+               }, 3000) // FIXME }, 30000)
        },
 
        beforeDestroy() {

Before	After