Treat RFB 3.6 as 3.3.

Apparently there are versions of UltraVNC that report version 3.6.
This is not a legal version according to the spec, but we'll just
force version 3.3 if we receive it. Thanks to Larry Rowe for the info.

include/rfb.js

@@ -682,6 +682,7 @@ init_msg = function() {
         Util.Info("Server ProtocolVersion: " + sversion);
         switch (sversion) {
             case "003.003": rfb_version = 3.3; break;
+            case "003.006": rfb_version = 3.3; break;  // UltraVNC
             case "003.007": rfb_version = 3.7; break;
             case "003.008": rfb_version = 3.8; break;
             default: