Fixing a duplicate addition exception that can occur if you launch a sim twice on the same grid.

OpenGrid.Framework.Data.DB4o/DB4oManager.cs

@@ -30,8 +30,15 @@ namespace OpenGrid.Framework.Data.DB4o
         /// <param name="row">The profile to add</param>
         /// <returns>Successful?</returns>
         public bool AddRow(SimProfileData row)
+        {
+            if (profiles.ContainsKey(row.UUID))
+            {
+                profiles[row.UUID] = row;
+            }
+            else
             {
                 profiles.Add(row.UUID, row);
+            }
 
             try
             {