Activates a user account by email. Requires the id of the user being activated and the secret. The link to activate a user account is generated by the register action and is inserted in the registration email.
<a href="/action/v2/activateaccount?u=555&s=72sdf34sD025ehtSFJBskdjfs6280hgM">Activate account</a>
|Numeric string - user id to confirm the account
|Secret string of 32 characters