server/rpki: fixed ROA sort

The typo in function Less() was causing logical error during comparison
and the comparison would always return whether AS number was less or not
regardless of Maxlen.

fixes #1633

server/rpki.go

@@ -65,9 +65,9 @@ func (r roas) Less(i, j int) bool {
 	r1 := r[i]
 	r2 := r[j]
 
-	if r1.MaxLen < r1.MaxLen {
+	if r1.MaxLen < r2.MaxLen {
 		return true
-	} else if r1.MaxLen > r1.MaxLen {
+	} else if r1.MaxLen > r2.MaxLen {
 		return false
 	}