GD 库安装疑难排解

• 报错信息：Exception: Depends: libjpeg62-turbo (>= 1.3.1) but it is not installable

  $ wget http://ftp.br.debian.org/debian/pool/main/libj/libjpeg-turbo/libjpeg62-turbo_1.5.2-2+b1_amd64.deb
  $ sudo dpkg -i libjpeg62-turbo_1.5.2-2+b1_amd64.deb
  $ apt install php7.3-gd

  测试环境：PHP7.3 on Ubuntu18.04