GUI Editor crash on CTRL + Right Click

Some reason i had the GUI editor crash on me if i right clicked a few times on a control while holding down CTRL. Problem appeared to be the Vector class attempting to erase an element in an empty vector.

Following stopped it for me. This should be tested further as many things appear to use this template.

template<class T> inline void Vector<T>::erase(iterator q)
{
    if (mElementCount)
		erase(U32(q - mArray));
}

template<class T> inline void Vector<T>::erase_fast(iterator q)
{
	if (mElementCount)	
		erase_fast(U32(q - mArray));
}