add dwz as a package to get from backports

The dwz is a dependency of debhelper, so we need to get the backports version just as we get the backports version of debhelper.

add dwz as a package to get from backports
6a1904f7 · Adam Lewenberg · 02b612ae · 6a1904f7
Commit 6a1904f7 authored 4 years ago by Adam Lewenberg
--- a/templates/etc/apt/preferences.d/debian-build.erb
+++ b/templates/etc/apt/preferences.d/debian-build.erb
@@ -6,6 +6,7 @@
    'debootstrap',
    'dh-autoreconf',
    'dh-strip-nondeterminism',
+    'dwz',
    'libfile-stripnondeterminism-perl',
    'pbuilder',
    'quilt',