security/vuxml: delist palemoon from CVE-2018-514[67]

Let upstream to decide if the browser is affected.
https://github.com/MoonchildProductions/Pale-Moon/commits/master/media/libvorbis/lib/vorbis_codebook.c
https://github.com/MoonchildProductions/Pale-Moon/commits/master/media/libtremor/lib/tremor_codebook.c