Averting of compression method override

Example of code:

    ::Zip::ZipFile.open("path_to.zip", ::Zip::ZipFile::CREATE) { |zip_content|
            entry_path = "test.txt"
            zip_entry = ::Zip::ZipEntry.new("", entry_path, "", "", 0, 0,::Zip::ZipEntry::STORED)
            zip_content.add zip_entry, entry
          end
      }

Without this fix file "test.txt" will be always compressed (using DEFLATED compression method)