no systray icon when dbus is available (DBUS_SESSION_BUS_ADDRESS or XDG_RUNTIME_DIR are set)

**Describe the bug**

On non KDE environment with many KDE elements systray icon is missed in lxpanel (and in fpanel too) on openbox when dbus is available (`DBUS_SESSION_BUS_ADDRESS` or `XDG_RUNTIME_DIR` are set).

CopyQ print warning on start:

> Warning: [default] QDBusTrayIcon encountered a D-Bus error: QDBusError("org.freedesktop.DBus.Error.UnknownObject", "No such object path '/StatusNotifierWatcher'")

After unset these env variables systray icon is show and work correctly.

Tested on 10.0.0 from Debian Trixie and on 13.0.0 from github.
(10.0.0 systray icon was missed also when `QT_QPA_PLATFORMTHEME` was set)

**To Reproduce**
(I'm not sure) run CopyQ on system with dbus but without "StatusNotifierWatcher"

**Version, OS and Environment**
CopyQ Clipboard Manager 13.0.0
Qt: 5.15.15
KNotifications: 5.116.0
Compiler: GCC
Arch: x86_64-little_endian-lp64
OS: Debian GNU/Linux 13 (trixie)