[PATCH v2 6/8] sphinx-pre-install: add dependencies for ImageMagick to work with svg

ImageMagick actually uses librsvg for conversions when converiting from SVG (actually, it uses rsvg-convert). That causes the build to fail with: WARNING: Error #1 when calling: /usr/bin/convert /home/mchehab/docs/Documentation/media/uapi/v4l/selection.svg

[PATCH v2 6/8] sphinx-pre-install: add dependencies for ImageMagick to work with svg

ImageMagick actually uses librsvg for conversions when converiting from SVG (actually, it uses rsvg-convert). That causes the build to fail with: WARNING: Error #1 when calling: /usr/bin/convert /home/mchehab/docs/Documentation/media/uapi/v4l/selection.svg