[0.86 Bug] Multiple notifications for destroyed resource

When an AI has stacked several armies on top of one another, and moves all of them to destroy one of your resources (in my case a scenic view) you get one warning message about it for each of the armies.  For example, the first time this happened, Magnar hit my scenic view with a stack of three armies, and I got three warning messages.  The second time, while I was rebuilding it, he hit it again with five armies, and I got five warning messages about it.  One would suffice, especially to remove confusion about whether more than one resource was destroyed.