fix account.conf permission

https://github.com/acmesh-official/acme.sh/issues/6708#issuecomment-3745737079

acme.sh

@@ -2358,6 +2358,7 @@ _setopt() {
   fi
   if [ ! -f "$__conf" ]; then
     touch "$__conf"
+    chmod 600 "$__conf"
   fi
   if [ -n "$(_tail_c 1 <"$__conf")" ]; then
     echo >>"$__conf"
@@ -6671,6 +6672,7 @@ _initconf() {
 #NO_TIMESTAMP=1
 
     " >"$ACCOUNT_CONF_PATH"
+    chmod 600 "$ACCOUNT_CONF_PATH"
   fi
 }