[qmusbmode] properly initialize connectCount

connectCount is an array of 3 size_t and we were initializing the first 2 elements only
yet were accessing the 3rd element without initialization in connectNotify()

valgrind output:
==14815== Conditional jump or move depends on uninitialised value(s)
==14815==    at 0x499732C: MeeGo::QmUSBMode::connectNotify(QMetaMethod const&) (qmusbmode.cpp:122)
==14815==    by 0x592EA4B: QMetaObjectPrivate::connect(QObject const*, int, QMetaObject const*, QObject const*, int, QMetaObject const*, int, int*) (qobject.cpp:3072)
==14815==    by 0x5931D57: QObject::connect(QObject const*, char const*, QObject const*, char const*, Qt::ConnectionType) (qobject.cpp:2537)