l18n: Reference to non-existent option

[rakekniven]

There is no option like "Restrict accounts to only share with accounts in their groups"

https://github.com/nextcloud/guests/blob/e3432d2268d89a0174ee9329b2089377c0e00a0e/src/views/GuestSettings.vue#L12

Reported at Transifex.

[susnux]

cc @skjnldsv