ddns-scripts: Adjust descriptions in Makefile for apk

ddns-scripts: Adjust descriptions in Makefile for apk

Having both double quotes and parentheses in package
description may lead into troublewith apk, if parentheses
are located so that they get passed "outside" the quoted
parameter, and get interpreted as a token for shell.

Example:
 ash: -c: line 1: syntax error near unexpected token `('
 bash: -c: line 1: `/OpenWrt/e8450/staging_dir/host/bin/fakeroot
 /OpenWrt/e8450/staging_dir/host/bin/apk mkpkg --info "name:ddns
 -scripts-pdns" --info "version:2.8.2-r51" --info "description:D
 ynamic DNS Client scripts extension for "PowerDNS" via API. It
 requires: "option param_opt(Optional Parameter)" to be a valid

Avoid that by using single quotes in the detailed descriptions.

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>