[FIX] mail: fix broken attachment reload on upload

Follow up on a35c7169

closes odoo/odoo#93295

X-original-commit: 28014c97191e28b9db3870cdf4460f4bf243feb5
Signed-off-by: Alexandre Kühn (aku) <aku@odoo.com>
Signed-off-by: Sébastien Theys (seb) <seb@odoo.com>

addons/mail/static/src/models/file_uploader.js

@@ -126,7 +126,7 @@ registerModel({
         async _performUpload({ files }) {
             const composer = this.composerView && this.composerView.composer; // save before async
             const thread = this.thread; // save before async
-            const chatter = this.chatterOwner; // save before async
+            const chatter = this.chatterOwner || this.attachmentBoxView && this.attachmentBoxView.chatter; // save before async
             const activity = this.activityView && this.activityView.activity; // save before async
             const uploadingAttachments = new Map();
             for (const file of files) {