Notification preferences set in the wiki administration are only valid for users that do not edit pages

Steps to reproduce :

• On a fresh new instance, create a user "toto"
• In the administration of the wiki, section "Others" -> "Notifications", make sure that notifications are disabled by default
• Log in with the user "toto", go in your profile, see that your notifications are disabled, that is normal : it's the default configuration that we just set in the admin
• Edit a page, for example Sandbox.WebHome and save it
• Go back in your profile, in your notification preferences
• Observe that now, your notifications are enabled for "Pages" modifications, both in the notification menu and by emails

This is an issue as administrators will think that the notification preferences that they are setting to their users are the ones that will be applied until the user decides to customize its preferences. Here, the user did not do anything to change its preferences.