write_buff fails on Ruby 1.8.7 due to missing String#byteslice

[sodabrew]

This code might never have hit the implicit else case before, because String#byteslice is not present in Ruby 1.8.7:
https://github.com/brightroll/unixrack/blob/master/lib/unixrack.rb#L64

      # buff could be UTF-8
      while true
        nw = io.syswrite(out_buff)
        nwritten = nwritten + nw
        break if nw == out_buff.bytesize
        out_buff = out_buff.byteslice(nw..-1)
      end
      nwritten
    end

[drudru]

cool - will check out - thx

[sodabrew]

I rewrote the version of this method that I ported into RQ based on the Backports gem's implementation of byteslice using the unpack method:
https://github.com/brightroll/rq/blob/master/code/protocol.rb#L76-87