readme: fix broken packaging badge URL

This patch fixes the URL of the Packaging badge that was resolving a
404 error.
We are here setting the correct address for the link and for the badge
download image.

Change-Id: Ibf6679006f4bd9a24e58afa0cca68343a8a839f4
Reviewed-by: Alexandre Lision <alexandre.lision@savoirfairelinux.com>
diff --git a/README.md b/README.md
index 7619c2f..5f234b8 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@
 
 | App | CI | Packaging
 | :-: | :-: | :-:
-| [![Download on the Play Store](https://img.shields.io/badge/download-play%20store-blue.svg)](https://play.google.com/store/apps/details?id=cx.ring) [![Download on F-Droid](https://img.shields.io/badge/download-fdroid-blue.svg)](https://f-droid.org/repository/browse/?fdid=cx.ring) | [![Build Status](http://test.savoirfairelinux.com/buildStatus/icon?job=ring-client-android)](http://test.savoirfairelinux.com/job/ring-client-android) | [![Build Status](http://test.savoirfairelinux.com/buildStatus/icon?job=ring-client-android-packaging)](http://test.savoirfairelinux.com/view/Ring/job/ring-client-android-packaging/)
+| [![Download on the Play Store](https://img.shields.io/badge/download-play%20store-blue.svg)](https://play.google.com/store/apps/details?id=cx.ring) [![Download on F-Droid](https://img.shields.io/badge/download-fdroid-blue.svg)](https://f-droid.org/repository/browse/?fdid=cx.ring) | [![Build Status](http://test.savoirfairelinux.com/buildStatus/icon?job=ring-client-android)](http://test.savoirfairelinux.com/job/ring-client-android) | [![Build Status](http://test.savoirfairelinux.com/buildStatus/icon?job=ring-packaging-client-android)](https://test.savoirfairelinux.com/job/ring-packaging-client-android/)
 
 ## Environment