Update IKEv2 script

- Disable MOBIKE when running on Synology NAS. MOBIKE is not supported
  on these systems and prevents IKEv2 from working if enabled.
  Ref: https://github.com/hwdsl2/docker-ipsec-vpn-server/issues/298

extras/ikev2setup.sh

@@ -151,7 +151,7 @@ confirm_or_abort() {
 show_header() {
 cat <<'EOF'
 
-IKEv2 Script   Copyright (c) 2020-2022 Lin Song   10 Jun 2022
+IKEv2 Script   Copyright (c) 2020-2022 Lin Song   18 Jun 2022
 
 EOF
 }
@@ -576,6 +576,9 @@ check_mobike_support() {
   if uname -a | grep -qi qnap; then
     mobike_support=0
   fi
+  if uname -a | grep -qi synology; then
+    mobike_support=0
+  fi
   if [ "$mobike_support" = "1" ]; then
     bigecho2 "Checking for MOBIKE support... available"
   else