legends.py: slight adjustment to swatch callout usage
legends.py: slight adjustment to swatch callout usage

kanarelo/reportlab,Distrotech/reportlab,Distrotech/reportlab,kanarelo/reportlab,kanarelo/reportlab,Distrotech/reportlab,Distrotech/reportlab,kanarelo/reportlab,kanarelo/reportlab,Distrotech/reportlab