KUniqueApplication seems to cause a crash on close.

I reported this as bug
https://bugs.kde.org/show_bug.cgi?id=344918

This is Kubuntu 15.04 beta with kf5 5.7 and qt 5.4.0

Muon moved away from it today (2015-03-06).

Application: konsole (konsole), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[KCrash Handler]
#6  0x00007f4b8af05233 in QString::~QString (this=0x2068278, __in_chrg=<optimized out>) at ../../include/QtCore/../../src/corelib/tools/qstring.h:992
#7  0x00007f4b8aefa8b2 in QDBusConnectionPrivate::~QDBusConnectionPrivate (this=this@entry=0x2068260, __in_chrg=<optimized out>) at qdbusintegrator.cpp:1046
#8  0x00007f4b8aefab70 in ~QDBusConnectionPrivate (this=0x2068260, __in_chrg=<optimized out>) at qdbusintegrator.cpp:1064
#9  QDBusConnectionPrivate::deleteYourself (this=0x2068260) at qdbusintegrator.cpp:1076
#10 0x00007f4b8aeeed95 in QDBusConnectionManager::~QDBusConnectionManager (this=0x7f4b8af5ace0 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>, __in_chrg=<optimized out>) at qdbusconnection.cpp:98
#11 0x00007f4b8aeeee49 in (anonymous namespace)::Q_QGS__q_manager::innerFunction()::Holder::~Holder() () at qdbusconnection.cpp:59
#12 0x00007f4b8a8596a9 in __run_exit_handlers (status=0, listp=0x7f4b8abdd6c8 <__exit_funcs>, run_list_atexit=run_list_atexit@entry=true) at exit.c:82
#13 0x00007f4b8a8596f5 in __GI_exit (status=<optimized out>) at exit.c:104
#14 0x00007f4b8a840ecc in __libc_start_main (main=0x400828 <main>, argc=1, argv=0x7fffa80447f8, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffa80447e8) at libc-start.c:321
#15 0x0000000000400739 in _start ()


Reproducible: Always

Steps to Reproduce:
1.run konsole
2.close konsole
3.crash