Minor improvement to better handle "non-app" bundles in OpenAction

Some applications utilize bundles as "containers" for their document formats. Such custom bundles often don't have info.plist in them. When these "non-app" bundle files are to be opened (as documents) by corresponding apps with OpenAction, **bundleIdentifier** returns nil (as no info.plist provided). While it cannot affect ControlPlane thanks to the try / catch block around the call of **runningApplicationsWithBundleIdentifier**, that method adds an internal assert message to the log. Let's add an extra "safety" check here.