Putting two vias like that will cause as much (if not more) of an impedance discontinuity as having a single via. Where is the reference plane for this trace?
I am not familiar with the silver ink thru technology. Why are you concerned with poor conductivity through the via?
Another question: Is this for USB 1.1 or 2.0? For 1.1 speeds, the via is a don't care. The signals aren't even fast enough to 'see' it. At 2.0 speeds, I really don't think you'd have an issue either, provided that you have a good return plane and a good, controlled impedance through the length of the trace leading up to the via.