Not to set empty string to source when there is no result
Not to set empty string to source when there is no result

AmeBel/opencog,andre-senna/opencog,andre-senna/opencog,andre-senna/opencog,AmeBel/opencog,AmeBel/opencog,andre-senna/opencog,AmeBel/opencog,AmeBel/opencog,andre-senna/opencog,andre-senna/opencog,AmeBel/opencog,andre-senna/opencog,AmeBel/opencog