package/cegui: add libfribidi optional dependency

libfribidi is an optional dependency (enabled by default) since version
0.8.0 and
https://github.com/cegui/cegui/commit/17974582e6b6a7d8f5853b0272433f130f82e52a



Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Tested-by: Bartosz <Bilas&lt;b.bilas@grinn-global.com>
Reviewed-by: Bartosz <Bilas&lt;b.bilas@grinn-global.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>