Revert "Enable and use the Debian jessie-proposed-updates APT repository,...

Revert "Enable and use the Debian jessie-proposed-updates APT repository, anticipating on the Jessie 8.3 point-release."

This reverts commit 2bf73b19.

Debian 8.3 has been released.

Fix-committed: #10898

config/chroot_apt/preferences

@@ -171,10 +171,6 @@ Package: *
 Pin: release o=Debian,n=jessie-updates
 Pin-Priority: 990
 
-Package: *
-Pin: release o=Debian,n=jessie-proposed-updates
-Pin-Priority: 990
-
 Package: *
 Pin: release o=Debian,n=jessie
 Pin-Priority: 990

config/chroot_sources/jessie-proposed-updates.binary

-jessie-proposed-updates.chroot
\ No newline at end of file

config/chroot_sources/jessie-proposed-updates.chroot

-deb http://ftp.us.debian.org/debian/ jessie-proposed-updates main contrib non-free