renamed 'Drop Quality' to 'Quality Treshold' to better describe what it does

diff --git a/Locale/enUS.lua b/Locale/enUS.lua
index 5fb7db2..7c39a63 100644
--- a/Locale/enUS.lua
+++ b/Locale/enUS.lua
@@ -108,7 +108,7 @@ BrokerGarbage.locale = {
 	showEarnedTitle = "Show Money Earned",
 	showEarnedText = "Toggles whether to show the tooltip line 'Money Earned'.",

-	dropQualityTitle = "Drop Quality",
+	dropQualityTitle = "Quality Treshold",
 	dropQualityText = "Select up to which treshold items may be listed as deletable. Default: Poor (0)",

 	moneyFormatTitle = "Money Format",