fixed warning message when new file index < previous index

src/OutputByOrbit.cc

@@ -74,8 +74,8 @@ void* OutputByOrbitStream::OutputFixedOrbits( Slice& out ) {
       }else{
 
 	if( new_index != outFile.getIndex() ) { // i.e new file should be opened
-	  if (outFile.getIndex() < new_index){
-	    LOG(WARNING) << tools::strerror("new file index < previous file index:");	    	
+	  if (outFile.getIndex() > new_index){
+	    LOG(WARNING) << "new file index: " << new_index << " < previous file index: " << outFile.getIndex();	    
 	  }
 	
 	  close_and_move_file();