Bug#858210: suggests alsa-base, which no longer exists

[Michael Biebl <biebl@debian.org>]

Package: education-thin-client
Version: 1.921
Severity: normal

alsa-base was a transitional dummy package in jessie and has been
removed for stretch.

Please drop the suggests in education-thin-client.

-- System Information:
Debian Release: 9.0
  APT prefers unstable-debug
  APT policy: (500, 'unstable-debug'), (500, 'unstable'), (200, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.9.0-2-amd64 (SMP w/4 CPU cores)
Locale: LANG=de_DE.utf8, LC_CTYPE=de_DE.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)