拆分卸载脚本，应该是：
postuninstall scriptlet (using /bin/sh):
if [ "$1" = 0 ]; then
/sbin/install-info --delete /usr/share/info/festival.info.gz /usr/share/info/dir --section "Accessibility" > /dev/null 2>&1
fi

/usr/share/info/festival.info.gz文件在卸载之后已经不存在了，所以报错。正确的方法应该是在卸载之前执行。

已处理：
!8:install-info should be executed before the help package is uninstalled
!9:install-info should be executed before the help package is uninstalled。
!10:install-info should be executed before the help package is uninstalled。
!11:install-info should be executed before the help package is uninstalled
!12:install-info should be executed before the help package is uninstalled。