Take into account organization logo medium size in the new Gardenia theme

Change-Id: I1c5c4e0c5252b27754954e145a51a370ad2cc9dc
Merge commit 'refs/changes/64/2364/1' of ssh://gerrit.tuleap.net:29418/tuleap into stable

* ssh://gerrit.tuleap.net:29418/tuleap:
  Take into account organization logo medium size in the new Gardenia theme
This is Tuleap 6.12.99.94

Change-Id: I3cad78b206dbe0d9dec061e6e617083e9bfb7ace