[stable-2.7] Fix dpkg_selections integration test.

Download package from S3 since the previous location no longer exists.
(cherry picked from commit fd56788a14)

Co-authored-by: Matt Clay <matt@mystile.com>

test/integration/targets/dpkg_selections/tasks/dpkg_selections.yaml

@@ -1,5 +1,5 @@
 - name: download and install old version of hello
-  apt: "deb=https://launchpad.net/ubuntu/+archive/primary/+files/hello_{{ hello_old_version }}_amd64.deb"
+  apt: "deb=https://s3.amazonaws.com/ansible-ci-files/test/integration/targets/dpkg_selections/hello_{{ hello_old_version }}_amd64.deb"
 
 - name: freeze version for hello
   dpkg_selections: