Modifying Debian changelog to build 6.3 version

Change-Id: I6c79d7c88f38e48d19b1c6d922a5ac286f16d845
Merge commit 'refs/changes/77/677/2' of ssh://gerrit.tuleap.net:29418/tuleap into tuleap-stable-master

* ssh://gerrit.tuleap.net:29418/tuleap:
  Modifying Debian changelog to build 6.3 version

Change-Id: I72fa7239a5c83498c631a8ba8f4ca77b1baf80e8