Revert "Revert "Add dummy changelog entry.""

Bring back the dummy changelog entry for Tails 2.2 in devel.

This reverts commit b3c1d92d.

debian/changelog

+tails (2.2) UNRELEASED; urgency=medium
+
+  * Dummy entry.
+
+ -- anonym <anonym@riseup.net>  Tue, 26 Jan 2016 02:32:45 +0100
+
 tails (2.0.1) unstable; urgency=medium
 
   * Major new features and changes