Make it so that failing to apply an effect will not remove an existing

instance of it.

game/engines/default/engine/interface/ActorTemporaryEffects.lua

@@ -107,7 +107,7 @@ function _M:setEffect(eff_id, dur, p, silent)
 	p.dur = dur
 	p.effect_id = eff_id
 	self:check("on_set_temporary_effect", eff_id, _M.tempeffect_def[eff_id], p)
-	if p.dur <= 0 then return self:removeEffect(eff_id) end
+	if p.dur <= 0 then return end
 
 	-- If we already have it, we check if it knows how to "merge", or else we remove it and re-add it
 	if self:hasEffect(eff_id) then
@@ -182,7 +182,7 @@ function _M:copyEffect(eff_id)
 	param.__tmpvals = nil
 
 	return param
-end 
+end
 
 --- Removes the effect
 function _M:removeAllEffects()