adjust DNSWL scores to -0.1/-0.2/-0.5

conf/scores.d/rbl_group.conf

@@ -29,11 +29,11 @@ symbols = {
         description = "Sender listed at https://www.dnswl.org, no trust";
     }
     "RCVD_IN_DNSWL_LOW" {
-        weight = -0.5;
+        weight = -0.1;
         description = "Sender listed at https://www.dnswl.org, low trust";
     }
     "RCVD_IN_DNSWL_MED" {
-        weight = -0.5;
+        weight = -0.2;
         description = "Sender listed at https://www.dnswl.org, medium trust";
     }
     "RCVD_IN_DNSWL_HI" {