Removed note re 'platform' line from readme.txt
Some of you were using this feature (as intended) to advertise that the
client was running on some other/fake/amusing BBS package and OS.  I'm
told that this is not okay and may break things in the future.  (If you
update mrc-connector.js, the fact that you're running Synchronet and on
Linux or Windows i386, i686, x86_64 will be shared with the MRC server.)