Fix retrieve code to allow multiple series download

This fix requires the dropNetwork branch of commontk/DCMTK in order to
build and run properly.

Libs/DICOM/Core/ctkDICOMRetrieve.cpp

@@ -237,11 +237,11 @@ bool ctkDICOMRetrievePrivate::retrieve ( QString UID, RetrieveType retriveType )
 
 
   delete responses;
-  //if ( !scu.dropNetwork().good() ) 
-    //{
-    //logger.error ( "Error dropping the network" );
-    //return false;
-    //}
+  if ( !scu.dropNetwork().good() ) 
+    {
+    logger.error ( "Error dropping the network" );
+    return false;
+    }
   return true;
 }