Fix the issue when window.currentlyLoadedIdentity set to null while executing...

Fix the issue when window.currentlyLoadedIdentity set to null while executing await loadIdentityInternal

javascript/src/iframe/viamapi-iframe.js

@@ -1277,7 +1277,7 @@ connection.promise.then(parent => {
       if (!pinCode) {
         if (!identityLoadedEvent) {
           const result = await loadIdentityInternal(window.currentlyLoadedIdentity.authentication.publicKey, "00000000");
-          if (result.code !== "200") {
+          if (window.currentlyLoadedIdentity && result.code !== "200") {
             const event = createEvent("CanNotLoadPincodeForLoadedIdentity", "IdentityNotLoaded", [window.currentlyLoadedIdentity.authentication.publicKey]);
             parent.onEvent(event);
             identityLoadedEvent = true;