[books] Short circut google lookup if it fails

vrobbler/apps/books/sources/google.py

@@ -29,6 +29,9 @@ def lookup_book_from_google(title: str) -> dict:
     google_result = (
         json.loads(response.content).get("items", [{}])[0].get("volumeInfo")
     )
+    if not google_result:
+        return {}
+
     publish_date = pendulum.parse(google_result.get("publishedDate"))
 
     isbn_13 = ""