Revert "Store default ruleset value for ability to revert"

This reverts commit cb7c2f713b.

osu.Game/Overlays/BeatmapSet/BeatmapRulesetSelector.cs

@@ -6,6 +6,7 @@ using osu.Framework.Graphics.UserInterface;
 using osu.Game.Beatmaps;
 using osu.Game.Rulesets;
 using System.Linq;
+using osu.Framework.Allocation;
 
 namespace osu.Game.Overlays.BeatmapSet
 {

osu.Game/Overlays/OverlayRulesetSelector.cs

@@ -26,7 +26,7 @@ namespace osu.Game.Overlays
                 var preferredRuleset = store.GetRuleset(api.LocalUser.Value.PlayMode);
 
                 if (preferredRuleset != null)
-                    Current.Value = Current.Default = preferredRuleset;
+                    Current.Value = preferredRuleset;
             }
         }
 

osu.Game/Rulesets/RulesetSelector.cs

@@ -33,7 +33,7 @@ namespace osu.Game.Rulesets
                 // That can become an issue with overlays that require access to the initial ruleset value
                 // before the ruleset selectors reached a LoadComplete state.
                 // (e.g. displaying RankingsOverlay for the first time).
-                Current.Value = Current.Default = Items.First();
+                Current.Value = Items.First();
             }
         }
     }