GUAC-1138: Use date format from translation string.

guacamole/src/main/webapp/app/manage/templates/manageSessions.html

@@ -66,7 +66,7 @@ THE SOFTWARE.
                         <input ng-change="wrapperSelectionChange(wrapper)" type="checkbox" ng-model="wrapper.checked" />
                     </td>
                     <td>{{wrapper.activeConnection.username}}</td>
-                    <td>{{wrapper.activeConnection.startDate | date:'short'}}</td>
+                    <td>{{wrapper.activeConnection.startDate | date:sessionDateFormat}}</td>
                     <td>{{wrapper.activeConnection.remoteHost}}</td>
                     <td>{{wrapper.name}}</td>
                 </tr>