Workaround for SRAS: if Store Asset returns 'null' then assume the asset already exists, and this isn't an error

OpenSim/Services/Connectors/Asset/AssetServicesConnector.cs

@@ -299,6 +299,13 @@ namespace OpenSim.Services.Connectors
                 return string.Empty;
             }
 
+            // TEMPORARY: SRAS returns 'null' when it's asked to store existing assets
+            if (newID == null)
+            {
+                m_log.DebugFormat("[ASSET CONNECTOR]: Storing of asset {0} returned null; assuming the asset already exists", asset.ID);
+                return asset.ID;
+            }
+
             if (string.IsNullOrEmpty(newID))
                 return string.Empty;