Remove RepairIndicator dependence on target RenderSimple.

This also fixes the case where the building palette doesn't
match the indicator, and saves 2 trait lookups per tick.

OpenRA.Mods.RA/Buildings/RepairableBuilding.cs

@@ -19,6 +19,7 @@ namespace OpenRA.Mods.RA.Buildings
 		public readonly int RepairPercent = 20;
 		public readonly int RepairInterval = 24;
 		public readonly int RepairStep = 7;
+		public readonly string IndicatorPalettePrefix = "player";
 
 		public object Create(ActorInitializer init) { return new RepairableBuilding(init.self, this); }
 	}
@@ -51,7 +52,7 @@ namespace OpenRA.Mods.RA.Buildings
 						Sound.PlayNotification(Repairer, "Speech", "Repairing", self.Owner.Country.Race);
 
 						self.World.AddFrameEndTask(
-							w => w.Add(new RepairIndicator(self, p)));
+							w => w.Add(new RepairIndicator(self, Info.IndicatorPalettePrefix, p)));
 					}
 				}
 			}