[FIX] mail: message sent twice because of the wrong tempId

task #3356870
Before this fix, at the first time of sending message in a chat, the tempId of the message in the chatter, crashes the getting lastMessageId and the first tempId in the chat becomes NaN.

closes odoo/odoo#125424

Signed-off-by: Alexandre Kühn (aku) <aku@odoo.com>

addons/mail/static/src/core/web/thread_service_patch.js

@@ -106,7 +106,7 @@ patch(ThreadService.prototype, "mail/core/web", {
             type: "chatter",
         });
         if (resId === false) {
-            const tmpId = `virtual${this.nextId++}`;
+            const tmpId = this.messageService.getNextTemporaryId();
             const tmpData = {
                 id: tmpId,
                 author: { id: this.store.self.id },