Fix issue with capturing enemy buildings in 'Intervention' mission

The onDamaged event handler would still fire after an enemy building had
been captured. Fixed by checking the owner before starting repairs.

Thanks to Microbit for showing me that people actually did that.

mods/ra/maps/intervention/mission.lua

@@ -188,7 +188,9 @@ SetupWorld = function()
 	Utils.Do(Actor.ActorsWithTrait("RepairableBuilding"), function(building)
 		if Actor.Owner(building) == soviets then
 			Actor.OnDamaged(building, function(b)
-				Actor.RepairBuilding(b)
+				if Actor.Owner(b) == soviets then
+					Actor.RepairBuilding(b)
+				end
 			end)
 		end
 	end)