_sandboxbuildboxrun: Fix check to enable action cache updates

The check was previously ignored if the user didn't have remote
execution / action cache configured.

Author: abderrahim

src/buildstream/sandbox/_sandboxbuildboxrun.py

@@ -132,8 +132,8 @@ def _execute_action(self, action, flags):
 
             if self.re_remote:
                 buildbox_command.append("--instance={}".format(self.re_remote.local_cas_instance_name))
-                if config.remote_apis_socket_action_cache_enable_update:
-                    buildbox_command.append("--nested-ac-enable-update")
+            if config.remote_apis_socket_action_cache_enable_update:
+                buildbox_command.append("--nested-ac-enable-update")
 
             # Do not redirect stdout/stderr
             if "no-logs-capture" in self._capabilities: