Fix valgrind warning on startup
Before KSldApp's constructor we call QObject::QObject. This calls setParent which triggers a ParentChangedEvent on the virtual from the constructor (boo!)
At this point our constructor hasn't run, so m_globalAccel isn't initiliased.
Arguably this is a false positive as it always evaluates to the same thing, but we don't want to be reading uninitialised memory.