Bug#856122: update: calf plug-ins do work, calf-ladspa conflict

[Dennis van Dok]

I've run some tests and debugging sessions; I noticed a few problematic
behaviours with the Calf plugins but they seem have a common origin.

I had both calf-plugins *and* calf-ladspa on my system, both containing
calf.so with a subtly different implementation. The latter packages
comes from lmms.

I removed calf-ladspa and now it seems to be ok.

I have not tried the Debian stretch package of ardour5 yet, I'm still
running my newer 5.9.0 build.