veyron/services/wsprd: Fix flag parsing for retryTimeout.
veyron/services/wsprd: Fix flag parsing for retryTimeout.

I also missed a call to Signature that needed the flag on in the
previous CL: https://veyron-review.googlesource.com/#/c/4592/

Change-Id: I97a4a5494a0cf8d09b40f3a82bd8e018c2f08bf0

vanadium/go.ref,vanadium/go.ref,vanadium/go.ref,vanadium/go.ref,vanadium/go.ref,vanadium/go.ref