新版本Directadmin已经支持4个版本的PHP共存，需搭配CustomBuild 2.0实现。
cd /usr/local/directadmin/custombuild
./build set php1_mode mod_php
./build set php2_mode mod_php
./build set php3_mode mod_php
./build set php4_mode mod_php
./build set php1_release 5.6
./build set php2_release 7.0
./build set php3_release 7.2
./build set php4_release 7.3
./build php n
./build rewrite_confs