Once again remove the additional ActivityDay class

It was previously removed in a44b5bf9ff
but got readded by accident in f274ffac4d.

SparkleShare/SparkleController.cs

@@ -1193,22 +1193,5 @@ namespace SparkleShare {
 	public class ChangeSet : SparkleCommit {
 
 	}
-
-	
-	// All commits that happened on a day	
-	public class ActivityDay : List <SparkleCommit>
-	{
-
-		public DateTime DateTime;
-
-		public ActivityDay (DateTime date_time)
-		{
-
-			DateTime = date_time;
-			DateTime = new DateTime (DateTime.Year, DateTime.Month, DateTime.Day);
-
-		}
-
-	}
 	
 }