fixed subscriber bug in main library

more info about the bug here:
http://stackoverflow.com/questions/22442890/spacebrew-locally-arduino-yun-web-page-subscriber-not-working

and here:
https://groups.google.com/forum/#!topic/spacebrew-cc/uxzPQFqFN-4

I've tested on my machine and it seems like it's solving the problem, please review as authors if this is a good solution.
cheers