A person subject to a licence under this Chapter must comply with such conditions as may for the time being be specified in the licence.
But where—
the licence relates to a sentence of imprisonment passed by a service court, and
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
the person is residing outside the British Islands,
the conditions specified in the licence apply to him only so far as it is practicable for him to comply with them where he is residing.