Revert "Fix report background image loading on Windows"

Forgot the proper backport markup...

This reverts commit b55fc8cd4caf363b16c586dc346965a3b615be62.

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/branches/2.4@23515 57a11ea4-9604-0410-9ed3-97b8803252fd
[23513]Fix report background image loading on Windows

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/branches/2.4@23516 57a11ea4-9604-0410-9ed3-97b8803252fd