Fix extraction of first warning in HL API.
Fix extraction of first warning in HL API.

Before we always returned the empty description, module, file and line of the dummy error.

ElektraInitiative/libelektra,ElektraInitiative/libelektra,ElektraInitiative/libelektra,mpranj/libelektra,mpranj/libelektra,mpranj/libelektra,mpranj/libelektra,mpranj/libelektra,ElektraInitiative/libelektra,mpranj/libelektra,ElektraInitiative/libelektra,mpranj/libelektra,ElektraInitiative/libelektra,mpranj/libelektra,mpranj/libelektra,ElektraInitiative/libelektra,mpranj/libelektra,mpranj/libelektra,ElektraInitiative/libelektra,ElektraInitiative/libelektra,ElektraInitiative/libelektra,ElektraInitiative/libelektra