[flatpak] fix -> not handling empty array API response when filling the app data asynchronously

bauh/gems/flatpak/worker.py

@@ -47,6 +47,9 @@ class FlatpakAsyncDataLoader(Thread):
                 if res and res.text:
                     data = res.json()
 
+                    if not data:
+                        self.logger.warning("No data returned for id {} ({})".format(self.app.id, self.app.name))
+                    else:
                         if not self.app.version:
                             self.app.version = data.get('version')