The D is not silent, it's very much pronounced.
In IPA, the correct French pronunciation of Django Reinhart's is /dʒɑ̃ɡo/ although most native English speakers who get it "correct" are happy to say /dʒæŋɡəʊ/. Notice the /d/ at the start.
EDIT: as clarified below, this wording is a little sloppy as it suggests /d͡ʒ/ is just the stop+fricative and not the affricate.