Merge pull request #332 from ably/simon/add-80024-unsupported-protocol-version

Add error code 80024 for unsupported protocol version

Author: SimonWoolf

protocol/errors.json

@@ -180,6 +180,7 @@
   "80021": "exceeded maximum permitted account-wide rate of creating new connections",
   "80022": "unable to continue current comet connection",
   "80023": "unable to resume connection from a different site",
+  "80024": "protocol version is no longer supported",
   "80030": "client restriction not satisfied",
 
   "90000": "channel operation failed",