No changes, just avoid unnecessary heap allocation in wxHtmlWindow.

Create the temporary wxClientDC on the stack, not the heap, there is no need
for the latter.

See #16501.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@77500 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Don't leave wxHtmlWinParser with a dangling wxDC pointer.

Call SetDC(NULL) to prevent wxHtmlWinParser from using a pointer to the
already destroyed wxDC object.

See #16501.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@77501 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775