Update firefox-esr.rb (#8570)
Update firefox-esr.rb (#8570)


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