Sorry for spamming the mailing list, but here's what probably happened: the Debian sync to update to version 0.4.1 actually happened yesterday, after the last successful build of urdf happened, so the last generated binary for urdf thinks it's on version 0.3.5. I actually think retriggering the binary job will work.
https://launchpad.net/ubuntu/+source/urdfdom (the Xenial release is dated 4/13)
I retriggered the binary job for Xenial amd64 only:
I'll probably need to retrigger the other binary jobs to avoid more failures due to packages dependent on urdf on other platforms. Going to wait to see if this fixes rviz before doing that