Duilib CPaintManagerUI::RemoveImage 资源泄漏 修复

在开发过程中，CPaintManagerUI::RemoveImage 函数调用，结果并没有释放掉image资源，一个小问题，修改一下可解决。

贴出修复可用代码：

void CPaintManagerUI::RemoveImage(LPCTSTR bitmap, bool bShared){TImageInfo* sdata = static_cast<TImageInfo*>(m_ResInfo.m_ImageHash.Find(bitmap));if (sdata){CRenderEngine::FreeImage(sdata);m_ResInfo.m_ImageHash.Remove(bitmap);return;}sdata = static_cast<TImageInfo*>(m_SharedResInfo.m_ImageHash.Find(bitmap));if (sdata){CRenderEngine::FreeImage(sdata);m_SharedResInfo.m_ImageHash.Remove(bitmap);return;}}