Add _cleardeployconf to clear deploy hook keys from domain conf

Mirrors _clearaccountconf_mutable: clears the SAVED_ prefixed key and
the legacy unprefixed key. Replaces the local copy in synology_dsm.sh
and the direct _cleardomainconf call in multideploy.sh.

Closes #4722. Thanks to @sg1888.

acme.sh

@@ -2594,6 +2594,13 @@ _savedeployconf() {
   _cleardomainconf "$1"
 }
 
+#key
+_cleardeployconf() {
+  _cleardomainconf "SAVED_$1"
+  #remove later
+  _cleardomainconf "$1"
+}
+
 #key
 _getdeployconf() {
   _rac_key="$1"

deploy/multideploy.sh

@@ -210,7 +210,7 @@ _clear_envs() {
 
   echo "$env_pairs" | while IFS='=' read -r _key _value; do
     _debug3 "Deleting key" "$_key"
-    _cleardomainconf "SAVED_$_key"
+    _cleardeployconf "$_key"
     unset -v "$_key"
   done
 }

deploy/synology_dsm.sh

@@ -424,11 +424,6 @@ _temp_admin_cleanup() {
   fi
 }
 
-#_cleardeployconf   key
-_cleardeployconf() {
-  _cleardomainconf "SAVED_$1"
-}
-
 # key
 _check2cleardeployconfexp() {
   _key="$1"