Don't change state to same state

The comment already stated as much, but the code was broken.

core/rfb.js

@@ -442,6 +442,7 @@
             if (state === oldstate) {
                 // Already here, ignore
                 Util.Debug("Already in state '" + state + "', ignoring");
+                return;
             }
 
             /*

tests/test.rfb.js

@@ -343,7 +343,10 @@ describe('Remote Frame Buffer Protocol Client', function() {
     describe('Page States', function () {
         describe('loaded', function () {
             var client;
-            beforeEach(function () { client = make_rfb(); });
+            beforeEach(function () {
+                client = make_rfb();
+                client._rfb_state = 'disconnected';
+            });
 
             it('should close any open WebSocket connection', function () {
                 sinon.spy(client._sock, 'close');