add cargo to firefox inputs

Julien LepillerThu Dec 14 00:00:20+0100 2017

4caa5e1

add cargo to firefox inputs

more/packages/gnuzilla.scm

236236
       ("pkg-config" ,pkg-config)
237237
       ("autoconf" ,autoconf-2.13)
238238
       ("which" ,which)
239-
       ("rust" ,rustc)))
239+
       ("rust" ,rustc)
240+
       ("cargo" ,cargo)))
240241
    (home-page "https://mozilla.org")
241242
    (synopsis "Web browser")
242243
    (description "")