Bug#1081529: education-desktop-other: Stop recommending freerdp2-x11

Control: severity -1 serious

I believe Debian Policy § 2.2.1 forbids a package in main having a
direct Depends or Recommends on packages that have been removed from
Debian. [1] I have filed a removal bug [2] for freerdp2 noting that it
is a security-sensitive library and I expect it to be removed from
Debian soon.

Michael Tokarev suggested it may be more appropriate for
education-desktop-other to completely remove its freerdp dependency
since it is not directly used.

gnome-core for instance depends on gnome-connections, an app that
could be used to connect to a desktop using GNOME's built in RDP-power
remote desktop solution.

[1] https://www.debian.org/doc/debian-policy/ch-archive.html#the-main-archive-area
[2] http://bugs.debian.org/1093460

Thank you,
Jeremy Bícha