Fix saving push_notification.conf as suggested by @robbiet480 (#3382)

homeassistant/components/notify/html5.py

@@ -144,7 +144,7 @@ def _save_config(filename, config):
     """Save configuration."""
     try:
         with open(filename, 'w') as fdesc:
-            fdesc.write(json.dumps(config, indent=4, sort_keys=True))
+            fdesc.write(json.dumps(config))
     except (IOError, TypeError) as error:
         _LOGGER.error('Saving config file failed: %s', error)
         return False