Code review comment for lp:~danilo/launchpad/bug-720826-links

Let's remove the distinct=True in the structural subscription code, as we discussed on IRC. It might have made some sense when we were not getting a result per filter, but does not now.

I asked for a test showing multiple filters and you said they existed in unit tests. I'm mostly OK with that as being sufficient here. :-)

Yay, thank you!