Fix sla #4653 : Office mimetype not recognized

Change-Id: I1d46a60c385f03ba3fbb614def1fefb351bd69c1
Merge commit 'refs/changes/34/834/6' of http://gerrit.tuleap.net/tuleap into HEAD

* http://gerrit.tuleap.net/tuleap:
  Fix sla #4653 : Office mimetype not recognized

Change-Id: I31d1f4156f62d6be87a1a2cdcf46780579d35118
This is Tuleap 6.4.99.1

Change-Id: I75ede7cc6aa92da9b9e3456f64d1b8604e55a120