Fix another infinite spin on register

Don't set ready on logging_in, set it before we start the client,
as commented

src/components/structures/MatrixChat.js

@@ -533,12 +533,10 @@ module.exports = React.createClass({
                 break;
             case 'on_logging_in':
                 // We are now logging in, so set the state to reflect that
-                // and also that we're not ready (we'll be marked as logged
-                // in once the login completes, then ready once the sync
-                // completes).
+                // NB. This does not touch 'ready' since if our dispatches
+                // are delayed, the sync could already have completed
                 this.setStateForNewView({
                     view: VIEWS.LOGGING_IN,
-                    ready: false,
                 });
                 break;
             case 'on_logged_in':
@@ -1012,6 +1010,10 @@ module.exports = React.createClass({
      */
     _onWillStartClient() {
         const self = this;
+        // if the client is about to start, we are, by definition, not ready.
+        // Set ready to false now, then it'll be set to true when the sync
+        // listener we set below fires.
+        this.setState({ready: false});
         const cli = MatrixClientPeg.get();
 
         // Allow the JS SDK to reap timeline events. This reduces the amount of