Fix email registration: pt. 1

We look to see if there's already a user logged in and if there is,
restore that session instead of logging the user in as their new
account. We still set this 'is_registered' flag though, even though
in that case it's not a newly registered account that's being restored,
so don't set in that case.

src/components/structures/MatrixChat.js

@@ -1733,9 +1733,6 @@ export default React.createClass({
 
     // returns a promise which resolves to the new MatrixClient
     onRegistered: function(credentials) {
-        // XXX: This should be in state or ideally store(s) because we risk not
-        //      rendering the most up-to-date view of state otherwise.
-        this._is_registered = true;
         if (this.state.register_session_id) {
             // The user came in through an email validation link. To avoid overwriting
             // their session, check to make sure the session isn't someone else.
@@ -1771,6 +1768,9 @@ export default React.createClass({
                 return MatrixClientPeg.get();
             }
         }
+        // XXX: This should be in state or ideally store(s) because we risk not
+        //      rendering the most up-to-date view of state otherwise.
+        this._is_registered = true;
         return Lifecycle.setLoggedIn(credentials);
     },