fix drawing non-closed lines in IMDraw

imdraw/imdraw.go

@@ -537,13 +537,16 @@ func (imd *IMDraw) polyline(thickness float64, closed bool) {
 
 		closing := false
 		if j >= len(points) {
-			if !closed {
+			/*if !closed {
 				break
-			}
+			}*/
 			j %= len(points)
 			closing = true
 		}
 		if k >= len(points) {
+			if !closed {
+				break
+			}
 			k %= len(points)
 		}