fix random selector

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

selector/random/random.go

@@ -22,7 +22,7 @@ func (r *random) Select(routes []string, opts ...selector.SelectOption) (selecto
 		}
 
 		// select a random route from the slice
-		return routes[rand.Intn(len(routes)-1)]
+		return routes[rand.Intn(len(routes))]
 	}, nil
 }