Remove new functionality (relies on code not yet in commontk/DCMTK)

Don't rely on new dropNetwork method -- it is not yet available in
our version of dcmtk.  This will be added back once the networking
is debugged for query/retrieve.

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;
 }