Code review comment for lp:~michihenning/thumbnailer/merge-crossbuild

I'm not convinced this is correct: while it might get rid of the dependency mess when running under crossbuild, it isn't clear that it is the right option if we were actually to attempt to run the tests.

Better would be to use build profiles to remove the dependency entirely in this configuration:

https://wiki.debian.org/BuildProfileSpec

Ideally we could change it to something like:

    python3-tornado <!nocheck>

But currently crossbuilder isn't setting that profile. It is setting the "cross" profile though, but we really want this tied to whether tests are being run rather than whether it is being cross compiled.