Do not create extra unknown reports in plugins launcher after plugin failures
At the moment for each verification tasks generator plugin failure there are 2 unknowns. The first one is correct, it corresponds to a failed plugin. The second one is excessive and corresponds to the plugins launcher.
Because of this issue we have more unknowns but worse is that nobody can compare results.
BTW, there still will be two unknowns if there will be a bug in the plugins launcher. But I hope that this will happen very rarely because of the plugins launcher does a trivial job.