fix(titus): Pass nextCommand if front50 app doesnt exist (#3966)

clouddriver-titus/src/main/groovy/com/netflix/spinnaker/clouddriver/titus/deploy/actions/LoadFront50App.java

@@ -120,7 +120,7 @@ public Result apply(@NotNull LoadFront50AppCommand command, @NotNull Saga saga)
       log.error("Failed to load front50 application attributes for {}", command.getAppName(), e);
       if (command.isAllowMissing()) {
         // It's ok to not load the front50 application
-        return new Result();
+        return new Result(command.nextCommand, Collections.emptyList());
       }
       throw new SystemException(
           format("Failed to load front50 application: %s", command.getAppName()), e);