build: Re-enable strict vala, disable deprecation
build: Re-enable strict vala, disable deprecation

Signed-off-by: Jens Georg <1d6e1cf70ec6f9ab28d3ea4b27a49a77654d370e@jensge.org>

Tarnyko/rygel,Pelagicore/Media-Manager-Rygel-patched,GNOME/rygel,Pelagicore/Media-Manager-Rygel-patched,GNOME/rygel,Tarnyko/rygel,GNOME/rygel,Pelagicore/Media-Manager-Rygel-patched