java8: use download.java.net (#6853)
java8: use download.java.net (#6853)

* java8: use download.java.net

* Update java8.rb

* Update java8.rb

rogeriopradoj/homebrew-versions,mahori/homebrew-versions,caskroom/homebrew-versions,victorpopkov/homebrew-versions,mahori/homebrew-cask-versions,rogeriopradoj/homebrew-versions,404NetworkError/homebrew-versions,404NetworkError/homebrew-versions,Ngrd/homebrew-versions,victorpopkov/homebrew-versions,pkq/homebrew-versions,pkq/homebrew-versions,Ngrd/homebrew-versions,lantrix/homebrew-versions,caskroom/homebrew-versions,lantrix/homebrew-versions