Safebox Memory Leak Fix

[frighter]

https://imgur.com/jGyQJAt

Find in safebox.cpp

    if (pkOldGrid)
        m_pkGrid = M2_NEW CGrid(pkOldGrid, 5, m_iSize);
    else
        m_pkGrid = M2_NEW CGrid(5, m_iSize);

delete existing block then add next

    if (pkOldGrid) {
        m_pkGrid = M2_NEW CGrid(pkOldGrid, 5, m_iSize);
        delete pkOldGrid;
    }
    else
        m_pkGrid = M2_NEW CGrid(5, m_iSize);