Bug#836154: sbuild --no-arch-any --no-arch-all --source fails on all only dsc

[Sam Hartman]

I want consistency between the case where there is a binary build and
the case where there is a source build.
I want --source because I want the source package to be included in the
.changes.
I want to use one tool, (sbuildh) rather than having my scripts care
about how it is being called.