Admins shouldn't be able to change the passwords of users

[canstudios-nicolaw]

Affected Area

User management

Requested Feature

Admin users shouldn't be able to change the password of other users, they should instead use the existing reset password button to send that user an email to reset their own password.

[canstudios-nicolaw]

Note: this is useful if smtp hasn't been set up. So this functionality will be disabled on servers which have smtp only. The config contains value 'useSmtp' which can be used to determine this.