Fixed CMYK issue in SetImageBackgroundColor.

git-svn-id: https://www.imagemagick.org/subversion/ImageMagick/trunk@16719 aa41f4f7-0bf4-0310-aa73-e5a19afd5a74
Fixed use of imageInfo in readImages.

git-svn-id: https://www.imagemagick.org/subversion/ImageMagick/trunk@16720 aa41f4f7-0bf4-0310-aa73-e5a19afd5a74