chatgui: localize file drop hints and attachment rejection messages

tools/chatgui/src/inputbar.cpp

@@ -220,7 +220,7 @@ void InputBar::installFileDropTarget(QWidget* target) {
     target->setAcceptDrops(true);
     target->installEventFilter(this);
     m_dropTargets.insert(target);
-    connect(target, &QObject::destroyed, this, [this, target] { m_dropTargets.remove(target); });
+    if (target != this) connect(target, &QObject::destroyed, this, [this, target] { m_dropTargets.remove(target); });
     GUI_DEBUG("InputBar: file drop target installed class=%s", target->metaObject()->className());
 }