Bring back convert nerf to fix overweighted taiko difficulty

Author: smoogipoo

osu.Game.Rulesets.Taiko/Difficulty/TaikoDifficultyCalculator.cs

@@ -87,6 +87,15 @@ protected override DifficultyAttributes CreateDifficultyAttributes(IBeatmap beat
             double combinedRating = combinedDifficultyValue(rhythm, colour, stamina);
             double starRating = rescale(combinedRating * 1.4);
 
+            // TODO: This is temporary measure as we don't detect abuse of multiple-input playstyles of converts within the current system.
+            if (beatmap.BeatmapInfo.Ruleset.OnlineID == 0)
+            {
+                starRating *= 0.925;
+                // For maps with low colour variance and high stamina requirement, multiple inputs are more likely to be abused.
+                if (colourRating < 2 && staminaRating > 8)
+                    starRating *= 0.80;
+            }
+
             HitWindows hitWindows = new TaikoHitWindows();
             hitWindows.SetDifficulty(beatmap.Difficulty.OverallDifficulty);