- Improve resilience in network & dns libs,

- Fix systemd scripts,
- Fix openvpn-up & openvpn-down scripts,
- Fix timing in vpn-admin_board.cgi script,
- Move systemd script from etc to usr.

lib/rx3/dns.bash

@@ -302,9 +302,9 @@ dns_host_update()
     local    ip="$3"
     local   ttl="$4"
 
-    local  date
+    local  date="$(date --rfc-3339=seconds)"
+    local    rc
 
-    date="$(date --rfc-3339=seconds)"
 
     log_info "DNS" "Host: [${host}]   Zone: [${zone}]   IP: [${ip}]   TTL: [${ttl}]   Date: [${date}]"
 
@@ -315,9 +315,9 @@ dns_host_update()
         echo "update delete  ${host}.${zone}. TXT"
         echo "update add     ${host}.${zone}. ${ttl} TXT ${date}"
         echo ""
-    ) | sudo nsupdate
+    ) | sudo nsupdate || rc="$?"
 
-    if [[ "$?" == "0" ]]
+    if [[ "${rc}" == "0" ]]
     then
         dns_tab_put "A" "${host}.${zone}" "${ip}"
     fi