package/libvips: add librsvg optional dependency

librsvg is an optional dependency which is enabled by default since
version 8.3.0 and
https://github.com/libvips/libvips/commit/153886d2eb71eebcdca860cb691d8fbb976ad816

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit adc0e0c6afc2011e6ef4d59a93c42f24399b8279)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
1 file changed