Updating the plugin configuration via Kaui does not reload the updated configuration in the UI

[reshmabidikar]

Steps to reproduce:

1. Ensure that the braintree plugin is installed and has a valid configuration in the database
2. Click on the tenant name in the top right and click on "Plugin Config"
3. Select braintree in the plugin name drop-down
4. Ensure that the existing configuration is loaded
5. Make changes to some properties
6. Click "Upload"
7. Select braintree in the plugin name drop-down

Expected Behavior: The new configuration uploaded at step 5 should be loaded
Actual Behavior: The old configuration (the one before upload) is loaded

The same issue is observed when the plugin configuration is uploaded via the "Config" link in the plugins page.