Fix seg fault in starter_cmd

When there is no status data on the /aos channel,
dereferencing the fetcher returns a nullptr for the starter Status.

Change-Id: Iad3606e5dc431d0f18722b13639c74d055956152
diff --git a/aos/starter/starter_rpc_lib.cc b/aos/starter/starter_rpc_lib.cc
index 67b3fb2..84b1a55 100644
--- a/aos/starter/starter_rpc_lib.cc
+++ b/aos/starter/starter_rpc_lib.cc
@@ -30,7 +30,7 @@
                                  const aos::Configuration *config) {
   std::string_view app_name = name;
   for (const auto app : *config->applications()) {
-    if (app->executable_name() != nullptr &&
+    if (app->has_executable_name() &&
         app->executable_name()->string_view() == name) {
       app_name = app->name()->string_view();
       break;
@@ -74,7 +74,7 @@
       event_loop.MakeFetcher<aos::starter::Status>("/aos");
   initial_status_fetcher.Fetch();
   auto initial_status =
-      initial_status_fetcher
+      initial_status_fetcher.get()
           ? FindApplicationStatus(*initial_status_fetcher, name)
           : nullptr;