check if the ip range is valid

ldap.go

@@ -34,11 +34,12 @@ func (l *ldapConfig) addIPRange(s string) error {
 	if len(ips) != 2 {
 		return errors.New("invalid IPs")
 	}
-	if ip := net.ParseIP(ips[0]); ip != nil {
-		l.ipMin = ip
-	}
-	if ip := net.ParseIP(ips[1]); ip != nil {
-		l.ipMax = ip
+	for k, v := range []*net.IP{&(l.ipMin), &(l.ipMax)} {
+		if ip := net.ParseIP(strings.Trim(ips[k], " ")); ip == nil {
+			return errors.New(fmt.Sprintf("invalid IP '%s'", ips[k]))
+		} else {
+			*v = ip
+		}
 	}
 	return nil
 }