The SSL Secure Connection checkbox cannot be selected

Created by: serenashe

Describe the bug The SSL Secure Connection button is invalid when configuring the email notifications.

The screenshot that shows the issue:

Versions used(KubeSphere/Kubernetes) KubeSphere: v3.1.0

To Reproduce Steps to reproduce the behavior:

1. Go to Platform Settings -> Notification Management -> Notification Configuration -> Email.
2. Under Server Settings, select the checkbox on the left of Use SSL Secure Connection.
3. You'll see that the checkbox cannot be selected.

Expected behavior The checkbox can be either selected or cleared according to the user's need.