Reword changelog

CHANGELOG.rst

@@ -21,7 +21,7 @@ Fixed
 * Only exactly one person without e-mail address could be invited
 * No person was created and linked to the PersonInvitation object when invite by e-mail is used
 * No valid data in the second e-mail field of the signup form when it was disabled
-* Invitation options were displayed even when the feature was disabled
+* Invitation options were displayed to superusers even when the feature was disabled
 * Inviting newly created persons for registration failed
 * Invited person was not displayed correctly in list of sent invitations
 * [Docker] Do not clear cache in migration container die to session invalidation issues