Fix for issue 2010.

The fix consists in including a little bit more on context to the error message.

For command-line dsconfig list-local-db-indexes --backend-name tasks -n -p 1389 -w s

The output was:

"Task Backend" is not a recognized component type

With the fix the output is:

"Task Backend" component type cannot be used with subcommand
{list-local-db-indexes}