Fix acmesh-official#4836 (Switch to new Gandi LiveDNS API)

1. Updated LiveDNS API URL for the new API to allow Personal Access Tokens to work
2. Updated authorization header syntax to allow deprecated API Keys to work with the new API

dnsapi/dns_gandi_livedns.sh

@@ -13,7 +13,7 @@
 #
 ########  Public functions #####################
 
-GANDI_LIVEDNS_API="https://dns.api.gandi.net/api/v5"
+GANDI_LIVEDNS_API="https://api.gandi.net/v5/livedns"
 
 #Usage: dns_gandi_livedns_add   _acme-challenge.www.domain.com   "XKrxpRBosdIKFzxW_CT3KLZNf6q0HG9i01zxXp5CPBs"
 dns_gandi_livedns_add() {
@@ -169,7 +169,7 @@ _gandi_livedns_rest() {
   if [ -n "$GANDI_LIVEDNS_TOKEN" ]; then
     export _H2="Authorization: Bearer $GANDI_LIVEDNS_TOKEN"
   else
-    export _H2="X-Api-Key: $GANDI_LIVEDNS_KEY"
+    export _H2="Authorization: Apikey $GANDI_LIVEDNS_KEY"
   fi
 
   if [ "$m" = "GET" ]; then