Fix most-specific zone match

Most specific zone selected by deepest sub-domain (how many '.' in the domain)
rather than seemingly irrelevant count of the number of characters within the zone.

dnsapi/dns_gcloud.sh

@@ -134,12 +134,12 @@ _dns_gcloud_find_zone() {
   filter="$filter)"
   _debug filter "$filter"
 
-  # List domains and find the longest match (in case of some levels of delegation)
+  # List domains and find the zone with the deepest sub-domain (in case of some levels of delegation)
   if ! match=$(gcloud dns managed-zones list \
     --format="value(name, dnsName)" \
     --filter="$filter" \
     | while read -r dnsName name; do
-      printf "%s\t%s\t%s\n" "${#dnsName}" "$dnsName" "$name"
+      printf "%s\t%s\t%s\n" "$(awk -F"." '{print NF-1}' <<< "$name")" "$dnsName" "$name"
     done \
     | sort -n -r | _head_n 1 | cut -f2,3 | grep '^.*'); then
     _err "_dns_gcloud_find_zone: Can't find a matching managed zone! Perhaps wrong project or gcloud credentials?"