Fix FPEs in AFP Monitoring Algs on cosmics

While investigating something else, I noticed two per-event FPEs originating in AFP-Monitoring in the Tier0 processing of recent cosmic data taking. Unsurprisingly, lbAverageInteractionsPerCrossing ends up 0.0 on cosmic runs, so we should not divide by this value to obtain a weight. The naive fix used here is to set it to 1.0.

BTW, I suspect, AFP monitoring should not be run at all on cosmics.