firefox-developer-edition.rb: remove cross-platform from desc (#9951)
firefox-developer-edition.rb: remove cross-platform from desc (#9951)




caskroom/homebrew-versions,404NetworkError/homebrew-versions,404NetworkError/homebrew-versions,mahori/homebrew-cask-versions,caskroom/homebrew-versions,pkq/homebrew-versions,pkq/homebrew-versions