If we find an existing suitcase folder in HGSuitcaseInventoryService.GetRootFolder(), then return that as a response rather than null.

Fixes a regression from commit 346644016c (Fri Nov 15 23:10:59 2013)
This is actually the reverse of zadark's patch in http://opensimulator.org/mantis/view.php?id=6969
But I'm assuming that was a mistake since clearly we should be returning this data - this was original behaviour

OpenSim/Services/HypergridService/HGSuitcaseInventoryService.cs

@@ -228,6 +228,10 @@ namespace OpenSim.Services.HypergridService
                     return ConvertToOpenSim(suitcase);
                 }
             }
+            else
+            {
+                return ConvertToOpenSim(suitcase);
+            }
 
             return null;
         }